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R O M E - 2 0 1 1 , S E P T E M B E R 1 4 T H - 1 7 T H

R O M E C AVA L I E R I H O T E L

1 5 T H B I E N N I A L C O N G R E S S

O F T H E E U R O P E A N S O C I E T Y

O F E N D O D O N T O L O G Y

ESE ROME 2011

ORAL SESSION

NOT ONLY ROOTS

ESE ROME 2011NOT ONLY ROOTS

1www.eserome2011.com

Cavalieri Hall IIITHURSDAY, 15TH SEPTEMBER 2011

14.30 / 19.00

ORAL PRESENTATION ON FREELY CHOSEN SUBJECTS 14.30 / 16.30

Chairperson: Zvi Metzger

14.30 – 14.50

Traumatised teeth and resorption: what do I tell the

orthodontist? Guido Aesaert, Ellen De Kempe Belgium

Abstract

Most traumata occur in children and youngsters. Management of traumatised teeth isn’t always easy. Furthermore most youngsters undergo orthodontic treatment during which forces are applied, this is an additional challenge. Will this infl uence the prognosis of trau-matised teeth?The presentation will give an overview of complications that could occur if orthodontic forces are applied on injured teeth. The partici-pants will be given guidelines based on literature considering what to advise the orthodontist: to stop treatment, to reduce forces or to pause the orthodontic treatment.In addition the management of unsalvable resorped teeth will be ex-plained to guarantee maximum success for implant placement.

14.50 – 15.10

Antimicrobial, tissue dissolution and stability of an elec-

trochemically activated solution (Aquatine, Sterilox) Giampiero Rossi-Fedele, L Steier, JAP Figueiredo Pontifi cal Catholic University of Rio Grande do Sul - PUCRS, Porto Alegre - RS - Brazil and University of Warwick,Coventry, UK

Abstract

Sterilox’s Aquatine (Optident, United Kingdom) consists of a mixture of oxidising substances including hypochlorous acid at a concentra-tion of 150-200mg/L, with a pH of 5.0-6.5 and a redox potential of >950mV; it is normally used for the disinfection of endoscopes and has been suggested as endodontic irrigant.To compare the antimicrobial action against Enterococcus faecalis in a bovine root canal model root sections were inoculated with E. faecalis. After 10 days of incubation the root canals were irrigated using one of three solutions (Sodium hypochlorite (NaOCl), saline or Aquatine) and subsequently sampled by grinding dentine using drills. The debris was placed in BHI broth and dilutions plated onto fresh agar plates to quantify growth. NaOCl was the only irrigant to eliminate all bacteria. When the di-lutions were made, although NaOCl was still statistically superior, Aquatine was superior to saline.To evaluate the tissue dissolution ability of Aquatine and NaOCl bo-vine pulp fragments were weighed and placed individually in Eppen-dorf tubes containing the tested solution until total dissolution oc-curred. Two blinded observers assessed the samples continuously for the fi rst two hours, and then every hour for the next 8 hours. Dis-solution speed was calculated by dividing pulp weight by dissolution time (mg/min).Pulp tissue was completely dissolved only by NaOCl.To understand the effect of storage conditions on Aquatine’s stability eight bottles (four completely full, four half-full) of freshly prepared solution were divided into four groups, and subsequently stored by being either exposed or protected from the sunlight. The chlorine concentration was monitored using test strips.

When exposed to sunlight, the decrease of available chlorine starts at day 4; meanwhile for the groups sheltered from sunlight, the process started after day 14. The presence of air did not affect the chlorine decomposition in the bottles.

15.10 – 15.30

Self-Adjusting File (SAF) in re-treatment: effective re-

moval of material left by the ProTaper re-treatment fi les

I Abramovitz, S Relles-Bonar, B Baransi, A Kfi r Department of Endodontics, The Hebrew University and Hadassa Faculty of Dental Medicine, Jerusalem, IsraelDepartment of Endodontology, The Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

Abstract

Effective re-treatment requires the removal of all previous root canal fi lling material. Modern rotary re-treatment fi les are very effective in removal of the main bulk of root canal fi lling material. Nevertheless substantial amounts of the material are left on the canal walls, espe-cially in the apical part of curved root canals. The Self-Adjusting File (SAF) fi le consists of a hollow tube of NiTi mesh which adapts itself three-dimensionally to the root canal walls with light pressure and is operated with a vibratory in-and-out mo-tion, thus creating a scrubbing effect. It was tested here as a supple-mentary tool for removal of root canal fi lling residues left in the canal by the rotary instruments.ProTaper re-treatment fi les were used to remove root canal fi llings from mesial roots of lower molars and the result evaluated radio-graphically. A drop of chloroform was then added and the SAF fi le was operated in the canal for 1 min to remove the root canal fi lling remnants left by the rotary instruments, followed by 4 min of SAF op-eration with sodium hypochlorite irrigation. The result was evaluated radiographically and compared to the above.Remnants of root canal fi lling material covered 35(±5%) of the apical third of the root canal area after application of the rotary re-treat-ment fi les alone. These remnants were substantially reduced to 7% (±2%) by a supplementary 1 min application of the SAF fi le with chlo-roform (p<0.0001).This study suggests that SAF fi le is a highly effective device for remov-ing root canal fi lling residues that are left in the canal after the applica-tion of rotary re-treatment fi les. It is effective even in the apical third of curved canals which are often inaccessible by other methods.The method is currently applied clinically and cases will be presented which demonstrate its application and effi cacy in the clinical environ-ment.

15.30 – 15.50

Evidence based endodontics: myths and factsAhmed Abdel Rahman HashemEndodontic Department, Faculty of Dentistry, Ain Shams University, Cairo, Egypt

Abstract

A lot of controversies are surrounding us in Endodontics. We are lacking high evidence based research in different fi elds. Most of our clinical decisions are based on personal opinions and invitro stud-ies. Bias is present in our treatment decision-making. This lecture will shed a light on different controversial issues in endodontics in-cluding Initial treatment: single or multiple, Instrumentation: taper or size, and type of root canal fi lling. At conclusion, every participant should be able to differentiate between high and low evidence-based research, and discuss the rational behind some of the techniques and materials used in Endodontics.






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15.50 – 16.10

Clinical evaluation of Biodentine in apical surgery: a 12

month follow-up study Francois Bronnec, G Caron, D Martin, P MachtouPrivate practice, Paris, France

Abstract

The study included 10 consecutive cases presenting with 15 lesions of endodontic origin without marginal periodontal involvement. After conventional surgical access, a limited root resection was performed when needed, and the canals were prepared ultrasonically at various depths depending on root canal anatomy, presence of a post, pres-ence and quality of previous root canal obturation. Cement (BioDen-tine, Septodont, Saint-Maur-des-Fossés, France) was prepared ac-cording to the manufacturer recommendations. The hydrated paste was obtained by mixing the powder and liquid in a high energy vibrat-ing device. The cement was carried in the apical root cavity using a specially designed triple-angled needle for retrograde obturation. After initial setting any excess material was removed by fl ushing the osseous crypt, and the retrofi llings were smoothed by using a fi ne grid diamond bur. Patients were recalled every 3-month after surgery for clinical and radiographical evaluation.Cases were defi ned as healed when no clinical symptoms were pres-ent and radiographs demonstrated complete bone reformation and normal periradicular appearance; incomplete healing when only partial reduction of the lesion occurred; uncertain outcome when no obvious change in size of the lesion could be shown; persistent dis-ease was defi ned as persistence of symptoms or fi stulous tract, or defi nitive absence of reduction in size of the lesion.Results: all the teeth were available for evaluation at 3-month: 7 showed complete healing, 6 showed incomplete healing, 2 were clas-sifi ed as uncertain outcome, none presented with clinical signs or symptoms. The results at 1-year will be presented during the con-gress.Conclusion: the rate of healed cases was comparable to that of other commonly accepted material. The novel tricalcium silicate-based ce-ment need further evaluation before it can be recommended for root end fi lling in apical surgery.

16.10 – 16.30

A 7-year follow-up of patients with atypical odontalgia

(AO) Maria Pigg, M Drangsholt, P Svensson, T List Faculty of Odontology, Malmö, Sweden University of Washington, Seattle, WA USA Aarhus University, Aarhus, Denmark

Abstract

Background and Aim: Atypical odontalgia (AO) is a severe chronic dentoalveolar pain condition with a prevalence of about 3% after endodontic treatment. The etiology is suggested to involve neuro-pathic pain mechanisms, possibly deafferentation of primary sensory neurons in dental pulp. Prior to correct diagnosis, patients with AO frequently undergo multiple and repeated endodontic treatments be-cause of unresolved pain. The aim of this prospective study was to examine the long-term prognosis of AO.Methods: The study included 43 patients diagnosed with AO. Base-line (2002) and follow-up (2009) data were collected by means of validated questionnaires and instruments including pain frequency, characteristic pain intensity (CPI 0-100 score), average pain intensity (0-100 numerical rating scale), graded chronic pain severity (GCPS), psychological status (depression and non-specifi c physical symp-toms scores of the SCL-90R according to the RDC/TMD) and a global improvement rating (PGIC). Baseline and follow-up data were com-pared using paired samples t-test at 5% signifi cance level.Results: 37 patients (86%) responded; 31 women and 6 men (mean

age 63, range 38-81 years). 62% reported continuous pain at baseline and 27% at follow-up (p=.001); 0% at baseline and 16% at follow-up had occasional pain (p=.012). CPI scores decreased from baseline 61±19 to follow-up 39±25 (p<.001). Average pain also decreased, from 5.7±2.0 to 3.5±2.4 (p<.001). 11% had GCPS scores indicating high dis-ability at follow-up compared to 32% at baseline (p=.003). 14% at follow-up and 0% at baseline reported no disability (p=.023). SCL-90R depression scores and non-specifi c physical symptoms scores showed no signifi cant differences between baseline and follow-up, but remained high.54% of the patients rated their global status as improved, 41% as unchanged and 5% as worse at follow-up.Conclusion: We conclude that a majority of AO patients experience pain reduction of some degree over time. Psychological status does not change accordingly.

16.30/17.00 COFFEE BREAK

17.00 / 18.40

Chairperson: Luigi Scagnoli

17.00 – 17.20

The evaluation of the cracks on resected root surfaces and

apical leakage in various retropreparation techniquesAydemir Seda, Cimilli Hale, Orucoglu Hasan, Kartal Nevin, Mumcu GoncaDepartment of Endodontics, Faculty of Dentistry, Marmara University, Istanbul, TurkeyDepartment of Endodontics, Faculty of Dentistry, Abant Izzet Baysal University, Bolu, TurkeyFaculty of Health Sciences, Marmara University, Istanbul, Turkey

Abstract

Aim: The purpose of this study was to evaluate and compare the root-end surfaces for the presence of cracks after the root-end cav-ity preparation with different retropreparation techniques and also evaluation of the apical leakage of root-end fi lling material.Material and methods: One hundred and twenty maxillary anterior extracted human teeth were used in this study. The root canals were prepared with Protaper instruments and obturated with lateral con-densation technique. Forty teeth were resected with tungsten carbid fi ssur burs and their retropreparations were performed with tung-sten carbid round burs at slow speed (conventional technique) and these teeth were used as control group (Group 1). The other eighty teeth were resected with Er:YAG laser and retropreparations were performed with Er:YAG laser (Group 2) and zirconium nitride coated ultrasonic retrotip (Group 3). Then, these groups were divided into two subgroups to examine number and types of cracks on the apical surfaces under stereomicroscope after resection and retroprepara-tion. Furthermore, the apical leakage of MTA using as a retrograde fi lling material was evaluated with fl uid fi ltration method.Results: According to the number and types of cracks no statistically signifi cant difference was detected between the conventional and the laser groups after apical resections, (p>0.05). After the retroprepa-rations, according to the number and types of cracks no signifi cant difference was found among three groups (p>0.05). The signifi cant differences in fl uid fi ltration test were found between Group 1/Group2 and Group 2/Group3 (p<0.05) while no signifi cant difference was shown between Group 1 and Group 3 (p>0.05).Conclusion: Under the circumstances of this study, it appeared that the retropreparations were performed with Er:YAG laser showed less leakage than ultrasonic and slow-speed hand piece.



17.20 – 17.40

Myths and facts of thermoplastic gutta-perchaBenjamin Briseño Marroquín, A Muñoz Stopa, D. Shürger, B. WillershausenDepartment of Operative Dentistry. Johannes Gutenberg University, Mainz, Germany

Abstract

Thermoplastic fi lling methods enhance the morphological adapta-tion properties of the fi lling materials. In order to achieve an ideal gutta-percha adaptation against the root canal system walls, gutta-percha must be heated during vertical condensation. For this pur-pose, different heat application devices (Touch’n Heat, System B, Ele-ments Obturation Unit and BeeFill 2 in 1) are commercially available. Endodontic gutta-percha plasticizes at approx. 68-70°C. Yet, gutta-percha is an ideal isolation material; thus, an accurate knowledge of its thermal conduction properties and devices characteristics is es-sential in order to be able to get gutta-percha to fl ow into all confi nes of the root canal morphology. The heat absorption and transportation potential of gutta-percha as well as the plasticizing devices proper-ties will be discussed in this presentation by means of scientifi c data.On one side it is necessary to know if the device set temperature is the one that reaches the tip of the heat carrier and if it is the right temperature amount to plasticize a gutta-percha point. On the other side it is vital to recognize the effect of the applied temperature at the different gutta-percha point levels. The data gained through different researches has shown inconsis-tencies between the selected temperature and/or power/intensity settings of different devices investigated. The temperature device settings do not correspond with the achieved temperatures and the temperatures achieved are far beyond the temperature required to plasticize gutta-percha. Furthermore, the differences between the applied and reached temperatures at different gutta-percha points levels demonstrated that gutta-percha has an extremely low heat transportation potential; thus, caution should be taken to place the heat-pluggers at the level were gutta-percha should plasticize to fa-cilitate an accurate compaction of the material.At conclusion participants should be able to evaluate the thermal conduction potential of gutta-percha and recognize the thermal properties of the device employed.

17.40 – 18.00

Ultramicroscopic study of the interface, sealing ability

and nanofi ltration of four different techniques for root

canal obturation Pablo Castelo Baz, Benjamin Martín Biedma, MM Lopes, M Ruíz, L Pires, J Silveira, Purifi cacion Varela Patino University School of Dentistry, Santiago de Compostela, Spain and University School of Dentistry, Lisbon, Portugal

Abstract

Introduction: the sealing of the root canal system after a good three-dimensional chemical-mechanical preparation is essential to obtain good results in endodontics. Gutta-percha has been the traditional material in endodontic fi lling. Resilon (Resilon Research LLC, Madi-son, CT) is advertised as an alternative to gutta-percha.Objective: compare the interface between the dentin and the obtura-tion material, the sealing ability and nanofi ltration of four root canal obturation methods with scanner electronic microscopy.Material and method: forty-eight extracted single-rooted maxillary teeth were endodonitcally treated and fi lled with gutta-percha/pulp canal sealer with (TH - thermafi l) or without (SB system B) plastic carrier and resilon/real seal with (RS1 - Real seal 1) or without plas-tic carrier (RS - Real seal). Specimens were analyzed with electron

microscopy using two methods: (a) fi eld emission scanning electron microscopy (FESEM) of the interface and (b) FESEM of the nanofi ltra-tion tests. Results: adhesive groups RS1 RS form hybrid layers but show sepa-ration areas (gaps) as conventional sealing groups (TH and SB). RS1 and RS showed similar separation to TH and SB groups in the apical, middle and coronal thirds. As for nanofi ltration, there was no differ-ence among the four groups. All had silver nitrate fi ltration in the three thirds.Conclusion: the sealing ability of the four obturation methods are similar in the interface, all groups present gaps. All groups present nanofi ltration in the tree thirds. We can conclude that the Resilon presents no advantage over traditional gutta-percha.

18.00 – 18.20

Microsyrgical endodontics: clinical-biological approachChristos SykarasDental School Athens GRSYNGCUK KIM DDS, PhD, MD(Hon)-University Of Pennsylvania USA

Abstract

Microsurgery is the surgical procedure, provided in a very small and complex anatomical area, with the use of an operation microscope. Many teeth endodontically treated, need to be retreated because of: broken/separated instruments, anatomical diffi culties (isthmus), iat-rogenic reasons (perforation), persistent infection. The majority of these teeth are retreated with conventional non-surgical procedures.In clinical Endodontics, microsurgery could be the most predictable, conservative and evidence-based procedure in cases of endodontic failure, compared with non surgical retreatment.The purpose of this presentation is to discuss the basic characteris-tics of Microsurgery and compare it with traditional endodontic sur-gery. The differences between the two methods will be highlighted. Microsurgical instruments, microscope, hemostasis, soft tissue management, osteotomy, root resection, root inspection, retroprepa-ration, and retrofi lling are the basic steps that will be mentioned.At last but not least , clinical and research data will be discussed about the success rate of endodontic microsurgery. Microsurgery is a well established procedure in clinical endodontics. In order to achieve the best success rate with microsurgical tech-niques the clinician must have: - knowledge of the anatomical complexity of the area- knowledge and experience of microsurgical techniques and proce-dures- proper microsurgical instrumentsIn addition it is very important to follow the basic sequence of micro-surgical procedures, that lead to better and faster healing.

18.20 – 18.40

C-shaped mandibular second molars. The clinical

challenge.A Mandas Theodoros, GJ Siskos, K Founta Postgraduate Student, Dept of Endodontics, Dental School of Athens UniversityAssociate Professor, Dept of Endodontics, Dental School of Athens UniversityPostgraduate Student, Dept of Dental Biomaterials, Dental School of Athens University

Abstract

The C-shaped mandibular molar was fi rst described by Cooke and Cox (1979). This name is related to the shape of the cross section of the root canal at its middle, resembling the letter C. Incidence of C-shaped mandibular second molars has been reported to vary be-tween 2.5 and 8%.Radiographic detection of the root canal morphological variation is diffi cult. This makes clinical recognition of the C-shaped canal un-






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likely, until access to the chamber is accomplished. Most C-shaped root canals vary in number, shape and interrelationship along the length of the root, which can make debridement and obturation a very diffi cult procedure.The coronal third should not be fl ared excessively to prevent perfora-tion or vertical root fracture during root canal preparation or coronal restoration. The use of ultrasonic instrumentation, increased volume of NaOCl, EDTA, and Ca(OH)2 as intracanal medicament between sessions have been proposed in an effort to achieve maximum de-bridement of the root canal system. Thermoplasticized gutta-percha techniques should be prefered.Furcation absence affects the surgical approach of such cases. Hemisection and root amputation are not feasible, whereas apicoec-tomy and retrofi lling may be diffi cult.Restoration of such teeth is compromised by the relatively thin ra-dicular walls. Canal preparation and application of prefabricated or cast posts may lead to strip perforation or fracture, later on.

cavalieri HALL IIIFRIDAY, 16TH SEPTEMBER 2011

8.30 / 18.40

ORAL PRESENTATION ON FREELY CHOSEN SUBJECTS 8.30/10.30

Chairperson: Matthias Zehnder

8.30 – 8.50

Microbiological implications in endodontic and dental

implant failuresDavid E. JaramilloAssistant Professor of EndodonticsDirector of Endodontics International Dentist Program Clinic Director of EndodonticsLoma Linda University School of Dentistry

Abstract

One of the major etiological factors for post-endodontic disease and dental implant failure is the presence of bacteria. Obtaining a positive outcome in both endodontic therapy and dental implant placement is highly dependent on the prevention and/or elimination of bacterial contamination. This presentation will demonstrate the presence of bacterial biofi lm by means of scanning electron and light microscopy and its possible role in endodontic and implant failure. At conclusion, participants should be able to:1. Discuss the role of bacteria in post-endodontic disease and dental implant failure.2. Identify strategies to prevent post-endodontic disease and dental implant failure.3. Discuss the indicators of success and failure of endodontic and dental implant therapy.

8.50 – 9.10

Quality of the root canal fi lling: validity of endodontic

leakage methodsMieke De Bruyne, AT Moinzadeh, RJG De Moor Ghent University Ghent University Hospital, Dental School, Department of Restorative Dentistry and EndodontologyBelgium

Abstract

Different techniques have been used to evaluate the quality of canal fi llings, among which a great deal of leakage methods. Although endodontic leak-age studies are subject of discussion, the seal of the root canal or the quality of the root canal fi lling remains an area of interest. A root canal fi lling is con-sidered ideal if a fl uid- and airtight seal can be achieved. If not, apical and coronal leakage may lead to endodontic failure by allowing microorganisms and their by-products to exert their pathogenicity on the peri-apex.Root canal fi llings may contain three different types of pores, being closed, blind and through pores. Closed pores entombed by the root canal fi lling will probably not infl uence leakage whereas blind pores, open to the apex and ending within the canal fi lling, may result in apical leakage and through pores, running along the complete length of the canal, in coronoapical percolation. To establish the validity of new or existing methods, there is no gold stan-dard available to compare to. Correlation between methods has only been evaluated in a very limited number of studies and different methods give different kinds of results which are diffi cult or impossible to compare. Clinical relevance for most methods is also diffi cult to determine and the link between the obtained results and the clinical impact might be ques-tioned. Apart from this, results evolve after time and most studies are short-term. Finally there is no information on the repeatibility of most methods. Hard-



ly any evidence is available on the fact whether results generated by a method are reproducible or not.For the future it appears that more research is needed towards fi nding a gold standard and establishing the validity of existing methods. Methods which don’t fulfi l the validity features will have to be discarded and re-placed by more sensible methods.

9.10 – 9.30

Smart root fi lling materials: the way to go?Dirk Mohn, Monika Marending, Thomas Imfeld, Wendelin J. Stark, Matthias ZehnderInstitute for Chemical and Bioengineering, ETH Zurich, Zurich, SwitzerlandClinic of Preventive Dentistry, Periodontology, and Cariology, University of Zurich, Center of Dental Medicine,Zurich, Switzerland

Abstract

After root canal debridement, a tight root fi lling that prevents re-en-tering of microorganisms into the canal system is considered to be an important step towards a favourable treatment outcome. However, chemomechanical root canal treatment does not necessarily result in complete microbial decontamination. Consequently, a root fi lling material with some antimicrobial properties could be useful.The current concept to fi ll root canals is to apply a core material that can be softened by heat and some type of sealer to adapt the core material to the canal wall. These sealers are often cytotoxic and may release monomers. Recent developments in biomaterials research could help to create a more biological approach to the application of foreign materials into the root canal system. With the introduction of Portland cement (MTA), alkaline biomaterials have found their way into endodontic practice. These materials initially have antimicrobial properties in a liquid environment, but later become inert. Materi-als that behave in this manner have been termed smart materials. Bioactive glass 45S5 is another alkaline biomaterial that has “smart” properties, which could be useful in endodontics.A consecutive development of a novel fi lling material, starting from the manufacturing of the key ingredient (bioactive glass), up to a fi nal formulation, was performed. Bioactive glass releases ions to form an apatite layer on its surface when immersed in a humid environment. This layer can bond to root dentine. Thus, a core material based on this concept could make sealers unnecessary. Additionally, bioactive glass has antibacterial properties and can be rendered radiopaque.This presentation will illustrate the concepts and technology that led to the development of bioactive gutta-percha. A comparison between this bio-gutta and conventional gutta-percha will be illustrated with respect to canal wall adaptation. Bio-gutta is a smart material that could be useful in multiple endodontic applications.

9.30 – 9.50

Cold treated vs. Heat treated Ni-Ti alloy rotary

instrumentsDina Al-SudaniKsu University Rijhad Saudi Arabia

Abstract

Ni-Ti alloy was introduced in endodontics two decades ago (Walia et al. 1988), for the superior elastic compliance it possesses over stain-less steel, rotary instruments fabricated from this alloy have become widely used in clinical practices. Since the introduction of nickel-tita-nium alloy to endodontics, there have been many changes in instru-ment design for the purpose to improve the mechanical properties. Just recently, a new manufacturing process of NiTi rotary fi les was developed in an attempt to obtain instruments that are more fl exible and resistant to fatigue. A proprietary thermomechanical processing procedure has been developed with the objective of producing su-perelastic NiTi wire blanks that contain substantial stable martensite under clinical conditions. This Phase transformation behavior has

an impact on the mechanical properties of NiTi instruments. and the former is easily infl uenced by factors including chemical composi-tion, heat treatment and manufacturing processes. The new manu-facturing process of NiTi rotary fi les was developed by subjecting the alloy to special heat treatment process at various temperatures to stabilize the martensite and premartensitic R phase which would re-sult in multiphase microstructure which will eliminate the feature of NiTi delicate response to a temperature change or a mechanical force as the former is due to the one-step phase transformation of B2 to B19 and the latter is due to the stress-induced austenite to mar-tensite (A-M) phase transformation. The purpose of this presentation is to compare the available conventional Rotary systems manufac-tured from cold worked Ni-Ti wires with the New heat treated Ni-Ti rotary systems in regard to the shape memory, super elastic proper-ties and fatigue resistance

9.50 – 10.10

Effectiveness of the Erbium: YAG laser activation in

removing the smear layer after root canal instrumentation,

using PIPS techniqueOlivi Giovanni, DiVito E.nrico, Benedicenti Stefano, Kaitsas VasiliosUniversity of Genoa, Faculty of Medicine and Surgery, School of dentistry, Restorative and Endodontics DepartmentPrivate practice Scottsdale, AZ-USA

Abstract

AIM: The aim of this study was to analyze in vitro, the debriding ability of an Erbium:YAG (Er) laser system (2,940 nm) equipped with a new design radial and stripped tip of 400 micron diameter, using a scan-ning electron microscopy (SEM) analysis.MATERIALS AND METHOD: Eighty (80) single-rooted recently ex-tracted human teeth were endodontically prepared with rotary in-strumentation and standardized chemical irrigation, using 5.25% sodium hypochlorite (NaOCl) and 17% ethylene diamine tetra acetic acid (EDTA), alternatively. At the end of mechanical instrumenta-tion, four different fi nal protocols were used: (G1) two minutes saline water irrigation as control group; the other groups (G2,G3,G4) were irradiated with an Er:laser at 20mJ, 15Hz, 50ms pulse durationw using the tip in the coronal opening of the wet root canal. Different solutions and irradiation time were used: (G2) 20 sec. Er:YAG laser irradiation in sterile distilled water wet canal; (G3) 20 sec. Er:YAG laser irradiation in 17% EDTA wet canal; (G4) 40 sec. Er:YAG laser irradiation in 17% EDTA wet canal. Scanning electron microscopy (SEM) analysis evaluated the debridement and smear layer removal at the apical third. RESULTS: The most effective removal of the smear layer from root canal walls was achieved by use of the Er:YAG laser plus EDTA fl ush-ing for 40 sec.(G4), the worst result was achieved fl ushing for two minutes the root canal with only saline water irrigation (G1).CONCLUSION: The study showed that standardized instrumentation, followed by a fi nal Er:YAG laser irradiation in EDTA wet canals, re-sulted in more cleaning of root canal walls and a higher quantity of open tubules in comparison with the traditional irrigation method.

10.10 – 10.30

Infl uence of the taper and the material of gutta-percha

thermocompactors on the sealer penetration in the

dentinal tubulesEric Balguerie, Lucas van der Sluis, Franck DiemerUniversity of Dentistry, Toulouse, France

Abstract

Aim: to evaluate if the material and the taper of gutta-percha ther-mocompactors have an infl uence on the sealer penetration in the dentinal tubules.Methods and Materials: Thirty-eight maxillary incisors were collect-ed and the root canals were instrumented until size 30 taper 0.06. The length of the root canals was standardized at 19mm. The teeth






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were divided in three groups of 12 teeth and 2 controls. In group 1, the gutta-percha was condensed with a thermocompactor of stain-less steel, size 30 taper 0.02, in group 2 with a thermocompactor of NiTi size 30 taper 0.02 and in group 3 with a thermocompactor of NiTi size 30 taper 0.04. After the fi lling procedure, the roots were longitu-dinally sectioned and SEM images were made of the interface dentin-sealer in the coronal, middle and apical root canal. Results: In the coronal root canal, the sealer penetration was signifi -cantly better in group 3. In the middle root canal, the sealer penetra-tion was signifi cantly better in group 2 and in the apical root canal there was no signifi cant difference between the groups. In group 1 and 3 the sealer penetration was signifi cantly better in the coronal root canal than the middle and apical root canal and there was no difference between the middle and apical root canal. In group 2 there was no difference between the coronal, middle or apical root canal.Conclusion: The sealer penetration in the dentinal tubules depends on the material and taper of the gutta-percha thermocompactor.


11.00 / 13.00

Chairperson: Imad About

11.00 – 11.20

Canal confi guration in the mesiobuccal root of the fi rst

maxillary molar using conventional computer tomographyEder Andreas, Moser Theresa, Nell AndreaBernhard Gottlieb University Clinic Vienna, Austria

Abstract

Aim: Observations of mesiobuccal roots of fi rst maxillary molars re-vealed inconclusive results.Methodolgy: In this study 1012 mesiobuccal roots in 582 patients were investigated by means of computer tomograpy (CT) examining the number of canals and their confi guration, allowing to observe a large number of teeth to get representative results at one time. Results: The observed canal confi gurations were classifi ed accord-ing to Weine and Vertucci classifi cation systems. Just 89 (8.8%) fi rst maxillary molars had only one canal in the mesiobuccal root while 39 (3.8%) showed a canal system that was more complicated than described by Vertucci.Conclusions: Considering these results dentists can save their patients from premature extraction of this tooth by searching better for a second or even third canal in the mesiobuccal root - if possible using CT. Key words: fi rst maxillary molar, dental CT, root canals, mesiobuccal canal confi guration.

11.20 – 11.40

Root canal shaping with only one instrument: continuous

rotation or reciprocity?Franck Diemer, Pauline Pecqueur, Jean-Philippe Mallet, Lucas van der SluisUniversity of Dentistry, Toulouse France

Abstract

The technology of root canal preparation is evolving. Shaping and cleaning principles are still unchanged but the method tends to be simplifi ed. Commercial pressure on one hand and desire of simplicity on the other hand want only one instrument to shape the root canal.The aim of this communication is to discuss the ability to prepare the root canal with nickel-titanium endodontic instruments designed for continuous rotary motion (M2, Protaper, HERO 642, HeroShaper, Revo-S or Race), normally or in reciprocity. All the instruments are size 25 0.06 taper at the tip or (F2). Each instrument, mounted on a fi xed contra angle, shaped endo-training blocs with alcohol irriga-tion. The resin simulator is fi xed on a mobile device. A 200g weight pulls it to the instrument. Irrigation and glide path are done at every

stop of the instrument progression or after auto-reverse. Indian ink colours in black the root canal, before and after preparation, which allows scanning of the resin blocks and defi ning the root canal. The analysis was done by superimposition of the two images allowing the measurement of transportation of the root canal with Image-J at each seven millimetres from the apex.Results show the different shapes of the root canal preparation (p<0,001) using continuous rotary motion or reciprocity movement.To conclude, the instrument design is decisive for both reciprocity or rotary motion.

11.40 – 12.00

Accumulated hard tissue debris during root canal

preparation evaluated using high resolution micro-

computed tomographyFrank PaquéDepartment of Preventive Dentistry, Periodontology, and Cariology, University of Zurich Center of Dental Medicine, Switzerland

Abstract

The aim of chemo-mechanical root canal preparation is to debride and disinfect the root canal system as thoroughly as possible to thus prevent or cure apical periodontitis. Recent laboratory research has utilized high resolution micro-computed tomography (μCT) to analyze and quantify hard tissue changes during root canal debridement. This technique is non-destructive and hence made it possible to analyze preparation effects in sequential assessments. Moreover, changes can be analyzed in three dimensions.The fi rst quantitative studies employing the technology have focused on changes in root canal anatomy caused by instrumentation. In es-sence, it was checked which aspects of the canal wall were removed or not mechanically cleaned. Recent advances in μCT image analysis have made it possible to visualize and quantify hard tissue debris, i.e. hard tissue fi lings that are accumulated during root canal instrumen-tation. Hard tissue debris accumulation was quantifi ed and depicted three-dimensionally in teeth with complex anatomy. The original im-ages were obtained from lower molars with multiple fi ns and rami-fi cations, which were instrumented without irrigation. These images suggested that hard tissue debris accumulation may be a side effect of root canal instrumentation that could be more dramatic than what had formerly been known as smear layer. During the last two years, several investigations have been undertaken to look at this specifi c topic, applying different types of irrigation and comparing different modes of instrumentation. This presentation will give an overview of different irrigation proto-cols during root canal instrumentation and their possible effects on hard tissue debris accumulation in irregularities of the root canal system. The latest results pertaining to the topic will be discussed and a review of the relevant literature will be given.

12.00 – 12.20

Medico-legal aspects of altered sensation following

endodontic treatment: a retrospective case seriesNavot Givol, Eyal Rosen, Lars Bjørndal, Silvio Taschieri, Igor TsesisDepartment of Preventive Dentistry, Department of Oral & Maxillofacial Surgery, The Chaim Sheba Medical Center, Tel Hashomer, Israel; Medical Risk Management Company, Tel Aviv, Israel. Department of Endodontol-ogy, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, IsraelDepartment of Cariology and Endodontology, University of Copenhagen, Copenhagen, Denmark.IRCCS Instituto Ortopedico Galeazzi, Department of Odontology, University of Milan, Milan, Italy

Abstract

The aim of the study was to analyze cases of liability claims re-lated to persistent altered sensation following endodontic treat-ments in order to characterize the medico-legal aspects of this complication.



A comprehensive search of an Israeli professional liability insur-ance database was conducted in order to retrospectively identify and analyze cases of persistent altered sensation following end-odontic treatment. Sixteen claims of persistent altered sensation following end-odontic treatments were identifi ed and analyzed. The typical pro-fi le of a claim was a female patient who underwent an endodontic treatment of a 2nd mandibular molar, which was associated with overfi lling. A signifi cant correlation between the tooth location and the suggested cause of nerve injury was found. None of the claims were initially reported by the practitioners, and all cases were identifi ed as a result of the patient’s demand for fi nancial compensation, either directly or by legal actions.When a nerve injury is diagnosed the treating practitioner should be encouraged to seek medical assistance in order to prevent permanent damage to the patient and to seek medico-legal ad-vice to enable a better legal response

12.20 – 12.40

New exciting challenges in modern endodonticsRaniero BarattoloPrivate practice, Bari, Italy

Abstract

New instruments and technologies have deeply changed the ap-proach to the root canal treatment. Every single phase can now be carried out faster and in a predictable way; due to the improvement of technology, it has become possible to successfully treat diffi cult cases. These extra opportunities may have implications in decision making, planning and evaluating root canal therapy. On the other hand, complicated anatomy and complex systems re-quest attention in the interpretation of pretreatment radiograph, various method of apical management, deep shape and correct ob-turation.Mechanical instrumentation, microbial control phase, and proper ob-turation are still critical steps of the root canal therapy.In particular, to control intracanal infection during the instrumenta-tion phase is the must. If performed correctly it will not only phisy-cally remove microbes from the canal wall but will also facilitate and magnify the effect of irrigants. Irrigants should be safely introduced, effectively remove biofi lm and eliminate the smear layer.At conclusion a variety of factors will be considered to help the clini-cian in choosing the proper preparation strategy in order to manage, negotiate and disinfect the apical third in diffi cult cases.

12.40 – 13.00

Achieving endodontic predictability in complex cases:

techniques and technology Filippo Santarcangelo Italy

Abstract

Successful endodontic treatment, in agreement with what prof. Schilder, the father of modern endodontics, enunciated, depends on the ability of the operator to mechanically and chemically clean the root canal system and subsequently obturate it three dimensionally. In diffi cult cases, each of the three phases of the root canal therapy is equally complex. Cases could be complex due to factors related to the patient, to the operator and to the tooth. As regards the latter, it should be remembered that canal anatomy, if complex, signifi cantly limits every part of the root canal treatment. Cases of curved, narrow and long canals are very challenging to manage and re-treatment is equally diffi cult, where the canal anatomy has been damaged or modifi ed by the previous operators. In light of the above, therefore, mastering endodontic techniques and enriching endodontic equip-ment with technology is a strategy that allows less experienced or

less gifted operators to attempt to solve complex cases. Thus root ca-nal treatment should be carried out with the aid of state of the art ap-pliances. However this is not all, the clinician needs something more. He should be able to master several kinds of endodontic technique: in other words nothing must be left to chance. At conclusion partici-pants will understand the crucial role that techniques and technology play in making root canal treatment predictable, not only in simple cases but also in more complex ones.The aim of this oral presentation is to highlight the possibilities and limits if modern cleaning.

13.00/14.30 LUNCH

14.30 / 16.30

Chairperson: Francesco Mangani

14.30 – 14.50

Effi cacy and safety of different irrigation and activation

systems: a new ultrasonic irrigation system using

aspirationUmberto Uccioli, Augusto Malentacca, Dario ZangariItaly

AbstractOne of the objectives of endodontic therapy is the removal of all the vital and necrotic tissue, microorganisms and microbial derivative products from the root canal system. The irrigation of the radicular canals with antibacterial solutions is considered an essential part of the chemical-mechanical preparation and the irrigation with a sy-ringe and needle remains the most commonly used method.Nowadays, many studies have demonstrated that the mechanical preparation and the normal methods of irrigation are not capable of assuring the optimal cleaning of the endodontic system due to the intricate nature of the anatomy of the radicular canal.Many authors have observed a noteworthy effectiveness after the passive use of ultrasound through a fi le in the canal fi lled with hypo-chlorite and they have called this technique PUI (Passive Ultrasonic Irrigation).Recently Nusstein and Others (2005) have proposed the use of a needle in the canal activated ultrasonically through which fl ows the hypochlorite, allowing for a continuous fl ow of irrigant.Studies conducted by the same authors in vitro and our observations both in models and in dissectins, have highlighted a noteworthy ef-fectiveness with this method in the cleaning of inaccessibleareas of the endodontium, defi nitely superior to those obtained with other ir-rigation methods. Alternatively, there was evidence for the potential to shoot the irrigation action beyond the normal distance whic it is moved by the frontal pressure of the syringe for the root canal cleaning.In fact, recent studies have shown evidence of absolute safety in the use of prssure cleaning systems are negative in respect to manual and ultrasonic irrigation, with particular reference to the ultrasonic needle, without underlining the clear superiority of the latter to pen-etrating and cleaning the endodontic space.Indeed, the issue about which is being debated is the necessity to have an effective irrigation system, but at the same time to not allow the excessive extrusion of irrigant.

14.50 – 15.10

Endodontic treatment: saving the tooth, or implant

insertion? The “middle ground” of modern dentistryFrancesco PeraDepartment of Endodontics, E. BeruttiUniversity of Turin Dental School, Turin, Italy

Abstract

The predictability of implant fi xtures as a long-term solution for edentulous areas has improved in recent years, to the point where they have become the standard of care in many situations. At the






8

same time, the success rates are very high for both endodontically-treated teeth and those requiring retreatment. Formulating a treat-ment plan, saving a tooth with RCT, or deciding for endodontic re-treatment, rather than extracting the tooth and replacing it with an endosseous implant, can give rise to interesting multidisciplinary debates. The decision-making process must consider numerous as-pects. A correct treatment plan will evaluate local and clinical diag-nosis, including the patient’s systemic condition. The possibility to restore the tooth and the long-term predictability of the procedure will be among key points of the discussion, as will the economic and biological costs of treatment. In the past the highest “biologic cost” of a treatment plan was assumed to be losing a tooth by extraction. Nowadays, however, in the era of implant rehabilitation, losing bone around a tooth that is to be replaced must be considered a high cost, since bone is as important a biological element as the tooth itself.

15.10 – 15.30

Improvements in NiTi alloys for the manufacturing of

endodontic instruments Nicola Maria Grande Sapienza University of Rome - Department of Endodontics

Abstract

The introduction of Nickel Titanium (NiTi) rotary instruments of greater tapers has been a revolutionary change in the fi eld of root ca-nal shaping and cleaning procedures. The fi rst proposal of the use of NiTi alloy for the manufacturing of endodontic instruments is dated more than 25 years ago. Since that time the advancements in the fi eld of NiTi rotary instruments regarded mainly the cross-sectional and fl utes design of the instruments, the variable tapers, the operative sequences, the surface treatments of the metal but not the metal-lurgical properties of the alloy, that remained unchanged for all the above-mentioned period of time.In the last years, however, research on new NiTi alloys and/or new manufacturing processes has been extremely active. New, innovative heat treatments performed before, during or after the manufactur-ing of endodontic instruments have been presented on the market to improve mechanical properties, and consequently clinical perfor-mance. It is now well known that by changing the thermal history of the alloy during the whole manufacturing process ( including the raw material), it is possible to modify the crystalline structure of the alloy, the different temperatures of austenite and martensite start and fi n-ish, and, consequently, all mechanical properties. To date, many dif-ferent proprietary thermal treatments have been proposed and new instruments manufactured with these new alloy formulations have been introduced in the market. In this lecture the basic mechanism of the thermal treatments will be analyzed, and experimental data about the different properties of the different alloys will be presented : fl exural and torsional properties, fatigue testing. Moreover in vitro and and clinical trials will be presented, in order to evaluate how these improvements in the alloys have an impact on the clinical per-formance of the NiTi instruments.

15.30 - 15.50

A comparative study between manual and mechanic

prefl aring techniquesKatia Greco, Enrico Carmignani, Giuseppe CantatoreUniversity School of Dentistry, Catanzaro, Italy Messina, ItalyUniversity School of Verona, Italy

Abstract

In the last years, Ni-Ti rotary fi les have been greatly improved in their manufacture properties so today they are more effi cient and safer in cutting, more fl exible in curved root canals, more resistant to the torsion load; in any case do not exist, nowadays, instruments without risk to separate during their use. Several researches, in literature, showed the importance of an ad-

equate manual pre-enlargement up to fi le # 20 so to reduce loading stresses and, consequently, risk of fracture of tapered rotary Ni-Ti fi les. An appropriate pre-fl aring should facilitate the creation of a glide path to tapered rotary Ni-Ti instruments; in this way they may advance easier in apical direction so to reduce the risk of taper lock. Traditional stainless steel instruments not always ensure a correct glide path for tapered rotary fi les for the risk to be cause of ledges, straightening or debris plugs. The use of dedicated rotary Ni-Ti in-struments ideated to obtain a correct glide path, seems to be a valid choice respect to the use of stainless steel fi les.The aim of our study was to assess the penetration of the irrigating solutions and the degree of apical extrusion of debris comparing the traditional pre-fl aring technique with stainless-steel hand fi les to a new one using rotary Ni-Ti .02 taper instruments (PathFiles, Maille-fer Dentsply, Swi).

15.50 - 16.10

Why our treatments should be aesthetics?Canon Gregory, Pierre MachtouDepartment of Endodontics and Restorative Dentistry, School of Dentistry,Pitie-Salpetriere Hospital, University of Paris 7, Paris, France

Abstract

The endodontic community is now unanimous on the main objectives of root canal (re)treatment : preserve or restore health of periradicu-lar tissues. In order to assess healing over time, several means could be used: clinical examination (persistent symptoms, probing, per-cussion) and radiographic interpretation (PAI with retroalveolar X-ray and CBCT scoring). However it could be very useful for the clinician to predict the success of root canal treatment at the end of fi lling procedure. The aim of this presentation is to show that following the principles described forty years ago by Schilder the clinician is the main predic-tor of success by respecting the biological and mechanical objec-tives. The outcome of endodontic treatment could be mainly based on the shaping look where a smooth taper and a right fl ow are essential. Thanks to several clinical cases and the latest literature this lecture will show that each step of the procedure (pretreatment, shaping, disinfection, fi lling, defi nitive reconstruction) should be validated with aesthetic guidelines in order to predict the (or to get an idea regarding) prognosis of endodontic treatment.

16.10 - 16.30

Endodontic treatment options of the immature root apexHolly Matthias, Klimscha J Bernhard GottliebUniversity Clinic of Dentistry, Vienna, Austria

Abstract

The endodontic treatment of traumatized or carious teeth with in-complete apexogeneses is a big challenge for the performing den-tist. With a structured strategic concept including correct diagnosis, knowledge of treatment prognosis and the right time for intervention in addition to regular controls most of eventual complications can be avoided. The main treatment option is to keep the vitality of the dental pulp, when possible, to obtain the maturation of the apex. In necrotic pulps the decision is how to achieve an apexifi cation, either induced through intracanal dressings with CaOH or iatrogenic by using MTA-cement. Each option will show its advantages and drawbacks. The aim of this presentation is to give an outline of the possible treatment options and their prognosis as well as to show the therapy manage-ment in several clinical cases. In conclusion the main factors for all treatment options are the management of infection and time of in-tervention.




17.00 / 19.00

Chairperson: Fabio Gorni

17.00 - 17.20

GTR improves the outcome of endodontic surgery in large

and through-and-through lesionsTsesis Igor, Eyal Rosen, Aviad Tamse, Silvio Taschieri, Massimo Del FabbroDepartment of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University,Tel Aviv, Israel andIRCCS Istituto Ortopedico Galeazzi, Department of Odontology, University of Milan, Milan, Italy

Abstract

The use of guided tissue regeneration (GTR) techniques has been proposed as an adjunct to endodontic surgery in order to promote bone healing. Studies assessing the added benefi ts of GTR for the outcome of endodontic surgery are highly variable in their treatment protocols, follow-up periods, and inclusion criteria, thus generating inconsistent and confusing results. The aim of this study is to evalu-ate the infl uence of GTR on the outcome of surgical endodontic treat-ment by means of a systematic review of the literature and meta-analysis.An exhaustive literature search combined with strict inclusion and exclusion criteria was undertaken to identify clinical studies that as-sessed the added benefi t of GTR in endodontic surgery.Lesion size, lesion type, and membrane type were identifi ed as fac-tors signifi cantly affecting the outcome of GTR versus control cases. GTR techniques favorably affected the outcome of surgical endodon-tic treatments in cases of large periapical lesions, and through-and-through lesions. A favorable outcome was found when using resorb-able membrane over using non-resorbable membrane or graft alone. GTR techniques may improve the outcome of surgical endodontic treatments in certain lesions. Additional large-scale prospective clinical studies are needed to further evaluate possible benefi ts of GTR techniques in endodontic surgery.

17.20 – 17.40

Drawing the line: detection of root canal fi lling interfaces

by microscopy and tomography methods Hagay Shemesh, P Zaslansky, P Fratzl, MK Wu, PR Wesselink Department of Endodontology, Academic Centre of Dentistry Amsterdam (ACTA), University of Amsterdam and VUUniversity, Amsterdam, The NetherlandsDepartment of Biomaterials, Max-Planck Institute of Colloids and Interfaces Potsdam Germany

Abstract

Aim: To quantify differences found in gutta-percha and canal cross-sectional areas imaged by three microscopy and two tomography methods.Methodology: Six roots fi lled with laterally compacted gutta-percha and AH26 sealer were scanned with phase-contrast enhanced micro-tomography (PCE-CT) in a synchrotron. 3D volumes of accentuated edges revealed micrometer-sized features within the whole treated roots. Reconstructed virtual slices were compared with sawed lon-gitudinal and crosssectional sections of both wet (n=2) and acrylic-embedded (n=2) samples, evaluated and measured using light and electron microscopy as well as by commercial lab-based micro-to-mography. Differing contrasts between the guttapercha, voids, sealer and root were noted. Inner canal border, outer gutta-percha rim and the external margin of a fi nger-spreader void were manually delin-eated and the enclosed areas were repeatedly (x3) measured by three observers. Inter-observer and inter-method areas were analyzed by 2-way ANOVA with Bonferroni adjustments (p<0.05) and percentages of gutta-percha fi lled canal areas (PGP) were determined.

Results: PCE-CT revealed clear interfaces and borders with area measurements matching those of wet polished crosssections. The other methods revealed different areas although PGP values differed by not more than 5% for the same slice. Although differences be-tween observers were sometimes signifi cant, the maximum differ-ence did not exceed 3%.Conclusions: PCE-CT is a powerful non-destructive in-vitro investi-gation method for studying the interfaces between root-canal walls and within fi llings. Caution should be used when attempting to quan-tify root-canal fi llings with measurements in conventional CT and light microscopy.

17.40 – 18.00

The apical third: anatomy, literature review, clinical

management. The role of instrumentation. Antonio Bonaccorso, Valeria Tripi, Marco Furri, Carlo Tocchio Private practice Catania, Private practice Verona, University of Padova Endodontics Departement

Abstract

The factors related to shaping the root canal apical third are pre-sented. Starting from a literatue review, the authors show how impo-trant is the detection of the three dimentions in the root canal system and the shaping ability.The rispect of the anatomy of the last three millimiters must be con-sidered mandatory and the literature shows that it is deeply related to the rotary fi les’ main features.Cross section, alloy, surface treatment, helix angle, torque and speed of rotations are intrinsic aspect of fi les able to infl uence the fi nal ri-sults of an endodontic treatment.The authors present how to achieve the goals of shaping the root canal system using both the anatomiv kwoledge and the instrumen-tarium.The showcase will present all of the aspects and strategies involved in the apical third management.

18.00 – 18.20

The apical third: anatomy, literature review, clinical

management. Antonio Bonaccorso, Valeria Tripi, Marco Furri, Carlo Tocchio Private practice Catania, Private practice Verona, University of Padova Endodontics Department

Abstract

The authors present the factors related to the management of the root canal apical third . Starting from a literatue review, they show how impotrant is the detection of the three dimentions in the root canal system. In particolar they focus on the concept of apical size, introducing the procedure of apical gauging Starting from anatomy the last three millimiters should be divided in: Apex, Foramen, Apical constriction and Cementum-Dentin-Junction, and the found classi-cal sudies reveal that their dimentions must be considered when the clinicians shape the root canal to obtain a good outcome. Increased apex preparations will allow a deeper cleaning and a more predict-able fi llig for better results in healing process.Another important aspect is the root canal cross section. The litera-ture has clearly shown that the section isn’t perfect round and the most common shape is the oval one.So the clinicians have to use their endodontic instruments in order to clean as well as possible the whole canal walls.The authors will show how to achieve the endodontic goals of clening an shaping the root canal system using both the anatomiv kwoledge and the instrumentarium.The showcase will present all of the aspects and strategies involved in the apical third management.






10

18.20 – 18.40

Ultrasonic aspiration technique in root canal irrigation Chihiro Kobayashi, T Yoshioka, H Suda Tokyo Medical and Dental University, Tokyo, Japan

Abstract

Aim To evaluate effi cacy of the newly developed ultrasonic aspiration technique (UAT). Methodology and Results We developed the UAT, which modifi ed the INP (Irrigation with Negative Pressure) by Fukumoto et al. Although INP is one of the safest irrigation methods, INP had the disadvan-tage that its thin aspiration needle was very easily choked with de-bris. In UAT, the aspiration needle itself is ultrasonically vibrated to avoid choking and increase irrigation effi cacy. For this purpose, we developed a new aspiration needle (iNP-40, Mikuni-Kogyo, Okaya, Japan). Its internal and external diameters are 0.26 mm and 0.35 mm, respectively. The effi cacy of UAT was evaluated measuring in-tensity of the permeating light through the transparent model. Inside the model, calcium hydroxide paste was fi lled. UAT was signifi cantly least time consuming and most effective comparing syringe irriga-tion, ultrasonic irrigation, and INP. Next, UAT was 3-demensionally evaluated using Micro-focus CT (SMX-225CT, Shimadzu, Kyoto, Ja-pan) in extracted teeth. Inside the canal, a contrast medium (Omnip-aque 350, Dai-Ichi-Sankyo, Tokyo, Japan) was fi lled. The volume of the remained contrast medium was signifi cantly smaller in UAT than in syringe irrigation. Then, possibility of UAT to clean periapical space and external root surface around the apical foramen was 3-demen-sionally evaluated with the same manner. The artifi cial periapical space of the extracted tooth model was fi lled with contrast medium and removal of it was evaluated. When the tip of the aspiration needle was placed 1 mm short of the apex, the contrast medium within 3 mm from the apex was removed. Conclusion UAT is safe, fast, and effective. Clinically, UAT was used for more than 1 year. Postoperative pain decreased and lateral canals were well fi lled.

cavalieri hALL IIISATURDAY, 17TH SEPTEMBER 2011

8.30 / 16.10

ORAL PRESENTATION ON FREELY CHOSEN SUBJECTS 8.30/10.10

Chairperson: Livio Gallottini

8.30 – 8.50

Middle mesial canal in mandibular molars: a review of

the literature and clinical casesGeorgios P. Dechouniotis, Xenos M. Petridis, Vasiliki Kondylidou, Maria K. GeorgopoulouGreece

Abstract

The anatomical complexity of the root canal system poses diagnos-tic and therapeutic challenges for the clinicians. Numerous studies on the morphological characteristics of the pulp cavity of permanent teeth have stressed that aberrations from the traditional concepts of internal tooth anatomy are quite frequent. The root canal anatomy of mandibular molars meets the criteria of being rather complex and its contribution to an endodontic failure should not be overlooked.The mesial root of the fi rst mandibular molar specifi cally, has gained the attention of many researchers and the occurrence of a third me-sial canal between the mesio-ligual and mesio-buccal canals has been described. In vitro studies and clinical reports have shown that the frequency of the so-called middle mesial canal varies, with its in-ternal path exhibiting variable morphology. Although rare, alertness regarding the identifi cation of an additional canal is imperative.Identifi cation of the middle mesial canal often requires more ad-vanced means than the angled periapical radiograph and the modi-fi cation of the access cavity. The dental operating microscope (DOM) and cone-beam computed tomography (CBCT) can reveal the exis-tence and the internal path of a middle mesial canal correspondingly, thus rendering its treatment a more predictable task. Also, the cur-rent technical equipment allows us to acknowledge similar morpho-logical patterns in roots whose canal anatomy has been underesti-mated, such as the mesial roots of second mandibular molars. The objective of this study is two-fold: fi rstly, to present a review of the literature regarding the existence and internal morphological di-versity of the third middle mesial canal in mandibular molars and secondly, to present clinical cases of endodontically treated mandib-ular molars exhibiting an additional mesial canal, in which DOM was a determinant for its identifi cation.

8.50 – 9.10

Dentin conditioning co-determines cell fate in regenerative

endodonticsGaller M. Kerstin, Rena N. D’Souza, Marianne Federlin, Adriana C. Cavender, Jeffrey D. Hartgerink, Gottfried SchmalzDepartment of Operative Dentistry and Periodontology, University of Regensburg, GermanyDepartment of Biomedical Sciences, Baylor College of Dentistry, Texas A&M, Dallas, USA Departments of Chemistry and Bioengineering, Rice University, Houston, USA

Abstract

Objectives: Recent successes in dental pulp engineering indicate that regenerative treatment strategies in endodontics are feasible. Clini-cally, revascularization procedures render completion of root for-mation in immature teeth. The generation of a pulp-like tissue after seeding of dental pulp stem cells into dentin disks or cylinders and



transplantation in vivo is possible. In this experimental set-up, which mimics the situation in the root canal, the pre-treatment of dentin might infl uence cellular behavior at the cell-dentin interface. Thus, the objective of this study was to investigate whether dentin condi-tioning can determine cell fate. METHODOLOGY Dental pulp stem cells (DPSC) were seeded into a growth-factor-laden peptide hydro-gel, transferred into dentin cylinders and transplanted subcutane-ously into immunocompromised mice. Prior to cell seeding, dentin cylinders were either pre-treated with sodium hypochloride (NaOCl) alone, or with NaOCl followed by a conditioning step with 5% EDTA. The constructs were explanted after 6 weeks and subjected to histo-logical (H&E, Masson’s Trichrome, TRAP) and immunohistochemical (Dentin sialoprotein, CD31) analysis. RESULTS. In dentin treated with NaOCl, resorption lacunae were found at the cell-dentin interface, created by multinucleated cells with clastic activity. After conditioning with EDTA, DPSC adjacent to the dentin formed an intimate association with the surface, differ-entiated into odontoblasts-like cells which expressed dentin sialo-protein, and extended cellular processes into the dentinal tubules. A vascularized soft connective tissue similar to dental pulp was observed inside the dentin cylinder. CONCLUSION The cell/growth-factor-containing hydrogel supported the formation of a pulp-like tissue. Dentin pretreatment effectively infl uences cellular interaction with the mineralized matrix and pulp stem cell differentiation, which might be an important aspect for future regenerative treatment strategies in endodontics.

9.10 – 9.30

Root fi llings performed with two root fi lling techniques,

an in vitro study using micro CT Moeller Lis Birkdal, A Wenzel, AM Wegge-Larsen, M Ding, LL KirkevangSchool of Dentistry, Faculty of Health Sciences, Aarhus University, DenmarkOdense University Hospital, Odense, Denmark

Abstract

Aim: The aim of this study was to compare the presence of voids in root fi llings performed in oval and ribbon-shaped canals with two root fi lling techniques, lateral compaction technique (LCT) or hybrid technique (HT), a combination of a gutta-percha masterpoint and Thermafi l. Furthermore the obturation time for the two techniques was evaluated.Methodology: Sixty-seven roots with oval and ribbon-shaped canals were included in the study. The canals were prepared using Profi le Ni-Ti rotary fi les. After preparation, the roots were randomly allocat-ed into two groups according to root fi lling technique. In both groups the roots were fi lled with AH+ and gutta-percha. Group 1 was fi lled using LCT (n=34) and group 2 was fi lled using HT (n=33). The time pe-riod from the canal was dry and ready to fi ll until the canal had been fi lled, was measured in 30 cases evenly distributed between the two techniques. Voids in relation to the root canal fi llings were assessed using cross-section images from Micro Computed Tomography scans (micro-CT).Results: None of the root canal fi llings were completely without voids. Scatter plots were used to illustrate the amount of voids de-tected in relation to the two root fi lling techniques. Permutation test showed no statistical signifi cant difference between the two root fi ll-ing techniques in relation to presence of voids (p=0.092). Permutation test on the difference in obturation time demonstrated a statistically signifi cant difference (p<0.001).Conclusion: The present study found no statistically signifi cant dif-ference in percentage of voids between two root fi lling techniques. A 40% reduction in obturation time was found for the HT compared to the LCT.

9.30 – 9.50

Reciprocation: better, safer, faster, smarter?Cristiano Fabiani, Vittorio FrancoItaly

Abstract

The introduction of Ni-Ti fi les into clinical practice has improved the quality of canal shaping, but increasing the curvature of the root ca-nal (or the diameter of the master instrument that prepares the full working length) could result in more transportation, straightening, and aberration of the canal. Usually Ni-Ti instruments were designed for use with continuous rotation movement at low speed. Recently, it has been suggested that Ni-Ti instruments could be used with a reciprocating movement. Ni-Ti instruments result signifi cantly safer and have an extended cyclic fatigue life when used with a recipro-cating movement. The time needed to shape canals should does not differ signifi cantly when instruments of bigger taper are used with the two different motions. This presentation will give an overview on the reasons why, when and how to adopt a reciprocating movement, showing results of studies on shaping ability, time of instrumenta-tion, and resistance of different instrument when used either in re-ciprocating movement or continuous rotation.

9.50 – 10.10

Operative strategies in non-surgical and surgical

retreatments Francesco MaggioreUniversity of Pennsylvania

Abstract

The ultimate goal of Endodontics, both Non-Surgical and Surgical, is to treat or to prevent endodontic pathology by properly cleaning, disinfecting and obturating the complete root canal system. With the achievement of new scientifi c acquisitions and the advancements of modern technologies challenging endododontic retreatments, once considered questionable, have became successful and predictable procedures. Furthermore the periapical lesions that cannot be treat-ed with an orthograde approach can now be completely solved by a microsurgical approach.Based on clinical evidence and supported by current literature, this presentation will illustrate a variety of clinical situations where end-odontic retreatments or endodontic microsurgeries are indicated. Clinical strategies, specifi c techniques, operative sequences will be in detail discussed and analysed in order to achieve in depth under-standing how to deal with recurrent endodontic infections maximiz-ing retaining of critical tooth structure.


11.00 / 13.00

Chairperson: Michele Barone

11.00 – 11.20

The association between chronic apical periodontitis,

oral health and coronary heart disease (chd)Damiano Pasqualini Assistant ProfessorDepartment of Endodontics – Prof. E. BeruttiUniversity of Turin Dental School– Turin, Italy

Abstract

Introduction: Acute coronary syndromes are one of the biggest public health problems in industrialised countries. In young patients, un-conventional risk factors appear to play a signifi cant role. Recently, the presence of chronic infl ammatory diseases, including those in the oral cavity, have been considered amongst possible risk factors.






12

Chronic periodontitis appears to be associated with an increased prevalence and incidence of coronary heart diseases (CHD). Apical periodontitis presents signifi cant similarities with chronic periodon-titis. but fi ndings concerning the systemic manifestations of the peri-apical infl ammatory process remain controversial.Among genetic risk factors, various studies have investigated the association between polymorphism of the promoter of gene CD14 C(-260)T and the different forms of disease associated with atheros-chlerosis. The aim of the study was to investigate two polymorphisms of the promoter of gene CD14 in the C(-159)T and C(-260)T positions, as markers of a predisposition to the onset of CHD, and to examine relations with the presence of chronic infl ammatory endodontic, and with oral health in general. The presentation aims to provide an overview of data currently avail-able in the literature, and illustrate a clinical study and provide some starting points for future research.A prospective case-control study was designed. CASES: 36 patients were recruited, (age <55y), non-diabetic, with known CHD. HEALTHY COTROLS were randomly recruited and then matched with the CAS-ES. After a dental examination and FMX, a diagnosis was formulated. A sample of blood was also taken to study genetic polymorphism. To evaluate the association of each variable with risk of CHD, a multi-variate analysis was done based on a logistic regression model.Results were the following: in the CASES (cardio) group, signifi cantly higher levels of oral pathology were found than in healthy subjects. The multivariate analysis showed a positive association between numbers of missing teeth (OR=1.47), caries (OR=1.30), endodontic lesions (OR=1.63), diagnosis of chronic periodontitis (OR=5.25) and CHD. The fi ndings concerning the preliminary evaluation of polymorphism of CD14 showed, in the CHD population, a markedly higher percent-age of homozygotic subjects for allele T than for allele C. By now no positive association emerged between polymorphism of the pro-moter of gene CD14 and the different levels of endodontic and peri-odontal disease. However preliminary data suggest further progress of the research.

11.20 – 11.40

Canal preparation using a single RECIPROC instrument

without glide path: research and clinical applicationsGhassan YaredCanada

Abstract

New concepts, instrument designs and preparation techniques are regularly introduced. However, the traditional (rotary) and newest concepts involve the use of numerous engine-driven and/or hand in-struments in different steps to achieve the desired canal shape.A simple canal preparation technique with only one engine-driven instrument used in reciprocation was introduced in 2008. The au-thor recommended establishing a glide path with hand fi les before applying the technique. However, only one instrument not designed for reciprocation and in one size was used, limiting consequently the number of canals which can be prepared with this technique. In addi-tion, the motor described in the article is not available on the market anymore. This presentation will introduce a new system (RECIPROC, VDW, Ger-many) specifi cally developed to be used with the single instrument reciprocation technique. The new system (motor and instruments in different sizes) allows the preparation of the majority of canals in-cluding large, and severely curved and narrow canals, with only one NiTi engine-driven instrument used in reciprocation and without cre-ating a glide path.The lecture will include:. the limitations of traditional rotary fi les and techniques. the rationale, advantages and limitations of reciprocation and sin-gle-fi le canal preparation with the RECOIPROC instrument without a glide path. the presentation of a technique using only one engine-driven instru-

ment in reciprocation for canal preparation and retreatment of gutta-percha and carrier-based obturations. the scientifi c evidence supporting the single fi le reciprocation con-cept

11.40 – 12.00

Light-Activated Disinfection: a new tool for improving

quality of root canal therapy Gianluca Plotino, Gianluca Gambarini Department of Endodontics, ‘Sapienza’ University of Rome, Rome, Italy

Abstract

Endodontic failure may occur in case of persistent bacteria in the root canal system as a consequence of poor disinfection and debridement of the endodontic space, untreated canals, inadequate fi lling or coro-nal leakage. It is well established that the elimination of pathogens from root canals during endodontic treatment is diffi cult and current endodontic techniques are unable to consistently disinfect the canal.Recently a novel method of disinfection for use in endodontics has be-come available. This is photo-activated disinfection (PAD). The prin-ciple on which it operates is that photo-sensitiser molecules attach to the membrane of the bacteria. Irradiation with light at a specifi c wavelength matched to the peak absorption of the photosensitiser leads to the production of singlet oxygen, which causes the bacterial cell wall to rupture killing the bacteria. Extensive laboratory stud-ies have shown that it is only the combination of photosensitiser and light which produces the effect on the bacteria. Using the principles described above, a system has been developed for endodontic use consisting of a lamp (FotoSan, CMS Dental APS, Copenhagen Den-mark). This antibacterial treatment has been called light activated disinfection (LAD). LAD, also called PACT (Photodynamic Antimicro-bial Chemo Therapy) is a treatment based on the combination of a photosensitizer and a powerful red light. Clinically, after completion of canal preparation, the canal is inoculated with the photosensitiser solution, which is left in situ for a fi xed period of time (60 seconds) to permit the solution to come into contact with the bacteria and diffuse through any biofi lm structure. The emitter is then placed in the root canal and irradiation carried out for 30 seconds each canal. This has been demonstrated in the laboratory study to kill high concentrations of bacteria generally found in root canals.

12.00 – 12.20

Disassembling and canal orifi ces location in complex non

surgical retreatmentsMauro CabidduUniversity of Turin, School of Dentistry, Department of Endodontics, Prof. Elio Berutti

Abstract

Non-surgical retreatments may present several diffi culties in the search for missing or hidden canals during cavity access. Conven-tional magnifi cation has proved not to be enough to show all the anat-omy details that enable the endodontist to work safely to preserve the tooth structure. There is no doubt that the clinical success and the structural resistence of the endodontically treated tooth, depend on the way the endodontist checks, explores and shape the endodontic space. The operative microscope and the use of ultrasonic tips, are of great help in managing this clinical step, providing the best control and facilitating treatment right through to the fi nal three-dimension-al apical sealing. The speaker will show how to deal with this clinical phase, pointing out the main steps to be completed in terms of ac-cess position, depth and extent in order to avoid all those mistakes that may hamper the achievement of optimal results.



12.20 – 12.40

Outcome of Root-Canal Treatments performed before

and after Education in Ni-Ti rotary Technique for GPs Margaretha Koch, E Wolf, K PeterssonUniversity, Faculty of Odontology, Malm, Sweden

Abstract

Aim. To retrospectively study the periapical status and root-fi lling quality >4 years after treatment, in teeth treated before and after an education for general practitioners in Ni-Ti Rotary technique (NiTiR). Materials and methods. The randomly selected sample constituted 824 patients, each participating with one root-canal treated tooth, 409 performed 2002 before, and 415 performed 2005, after the edu-cation. Periapical status was assessed according to the periapical index (PAI). Root-fi llings were judged as adequate or non adequate based on quality of seal and apex distance. This preliminary report presents fi ndings from a clinical and radiographic examination in 2009. Results. 207 (51%) of the 409 treatments performed in 2002 and 288 (69%) of the 415 treatments performed in 2005 were exam-ined in 2009. At follow-up 52 (13%) of the teeth root fi lled 2002 and 14 (3%) of the teeth root fi lled 2005 were extracted. The frequency of apical periodontitis judged as PAI 3+4+5 was 34% in teeth root fi lled before and 36% in teeth root fi lled after the education. The more evi-dent periapical lesions judged as PAI 4+5 seemed to be less frequent (11%) in teeth root fi lled in 2005 after the education in NiTiR com-pared to in the teeth root fi lled 2002 before the education (16%). How-ever the difference was not statistically signifi cant.Signifi cantly more of the root-fi llings performed 2005 were ad-equately sealed (50%) compared to of the root-fi llings performed 2002 (37%). Conclusions. A better technical quality of root-fi llings performed after the education in NiTiR-technique compared to be-fore the education was found in this study. A subsequent signifi cant improvement of the periapical status was not observed. Possibly, the more frequent extraction of teeth root fi lled before compared to after the education may have infl uenced the periapical status at follow-up.

12.40 – 13.00

Lateral canals and apical ramifi cations.

Tissue responses during the pulp degeneration process

and their impact on the treatment outcome.Domenico RicucciItaly

Abstract

The early histological events that can be observed when pulp is pen-etrated by bacteria are discussed. Necrosis and bacteria are initially confi ned to the pulp chamber, but soon pulp degeneration process extends beyond root canal orifi ces and moves slowly in an apical direction, with or without clinical symptoms. In histologic sections bacteria are often observed to form complex structures adhering to the root canal walls, known as “biofi lms”. These may be observed in lateral canals and apical ramifi cations, and only their complete elim-ination will lead to endodontic success. Tissue biopsies from failed cases demonstrate how infection from the apical root canal walls or from complex spaces can hardly be controlled with common treat-ment procedures. Chemomechanical preparation seems to remove only partially necrotic tissue from the entrance of LC/AR, while the adjacent tissue remains infl amed, sometimes infected, and associ-ated with periradicular disease. Vital tissue in ramifi cations is not removed by preparation. In cases where lateral canals appear radio-graphically “fi lled”, they are actually not obturated, and the remain-ing tissue in the ramifi cation is infl amed and enmeshed with the fi ll-ing material. Overall, the belief that lateral canals need to be injected with fi lling material to maximize treatment outcome is neither sup-ported by literature review nor by histopathological observations. For some teeth with apical periodontitis, it appears that strategies other than fi nding a technique that better squeezes sealer or gutta-percha

within ramifi cations should be pursued to effectively disinfect these regions. : At conclusion, participants should be able to:

• Describe important aspects of bacterial colonization of the root ca-nal system and the periapical area• Discuss the impact of lateral canals/apical ramifi cations in the out-come of endodontic treatment• List current limitations of contemporary root canal instrumentation and obturation procedures in obtaining a bacteria-free endodontic environment

13.00/14.30 LUNCH

14.30 / 16.10

Chairperson: Silvio Taschieri

14.30 – 14.50

MTA: clinical applicationsMassimo Giovarruscio, Umberto Uccioli Specialist in Endodontics Bristol Endodontic Clinic and Clinical Teache Conservative Department, King’s College, London Dental Institute, UKPrivate practice Frosinone, Italy

Abstract

Mineral trioxide aggragate (MTA) has emerged as a reliable bioactive material with extended applications in endodontics that include the obturation of the root canal space. The obturation of the prepared radicular space has been achieved by using a wide variety of materi-als selected for their intrinsic properties and handling characteris-tics. These core materials have been classifi ed as cements, pastes, plastics or solid. Gutta-percha, in its various forms, has remained the paragon as a root canal fi lling material during the course of the last century. MTA might have a profound advantage when used as canal obturation material because of its superior physiochemical and bioactive properties. This oral presentation suggests methods for its delivery and placement in the wide root canal and presents clinical cases that demonstrate its effectiveness in resolving apical periodon-titis under a variety of circumstances.Case reports are presented documenting clinical outcomes after the application of MTA that include retreatment, obturation open apices, perforation repair, internal resorption, and in conventional endodon-tic therapy. The author introduce clinicians to an alternative treat-ment strategy that might improve the healing outcomes for patients presenting with complex and challenging endodontic condition.

14.50 – 15.10

The advantages of use of operative microscope in clinical

and surgical endodontics Mario Lendini University of Turin, Turin, Italy

Abstract

Microscope and ultrasounds today are essential and reliable instru-ments in clinical and surgical endodontics. The opening of the pulp chamber is one of most important steps in endodontic therapy. It can affect the result and the success of the treatment particularly when using NI-TI rotary instruments. Best results can be achieved using ultrasounds together with magnifi cation. This lecture will analyze the different fi elds of use of ultrasounds with the microscope relating them with available technology and different clinical and surgical ap-plications. During the lecture we will also examine the management of soft tissues and bone access in endodontic surgery by microscope.Particular attention will be paid to clinical and surgical endodontic procedures: - to improve access by removing interferences- disassembly in retreatment- locating calcifi ed orifi ces






14

- removal of fractured instruments, posts, stones and fi lling materi-als- management of root perforations and altered apical anatomy- surgical access in the vicinity of anatomical areas at risk- preparing the bone cavity and preparing and fi lling the retro-cavityDuring the lecture some videos of clinical and surgical cases will be presented.

15.10 – 15.30

Historical and contemporary challenges to the

management of the root apexJames L. GutmannUSA

Abstract

There have been many empirical directives that have attempted to defi ne the exact location for the termination of root canal procedures and fi lling materials. Most are based on the ultimate assessment of a twodimensionalradiograph, presence or absence of patient symptoms and patient pain-free function upon subsequent re-examinations. However, there is little biologic data on the ultimate and ideal apical goal of root canal procedures,which is complete periapical tissue regeneration and it implications in successful outcomes and disease prevention. Yet, in the delivery of contemporary endodontic procedures there is little focus on this biologic concept. Thispresentation will explore the historical roots of this “apical dilemma” and focus on the contemporary, biologic perspectives and best-evi-dence available that should guide clinical choices.

15.30 – 15.50

Differential diagnosis and monitoring of periapical

lesions using ultrasound and color power doppler or CT Kececi Ayse Diljin, B Kaya Üreyen, G Koçer, M Cina Aksoy, M Gündüz, M Çetin, ED Üstün Suleyman Demirel University, Faculty of Dentistry, Department of Endodontics, Isparta, TurkeySuleyman Demirel University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery, Isparta, Turkey Suleyman Demirel University, Faculty of Medicine, Department of Radiology, Isparta, Turkey

Abstract

Aim: To evaluate the effi cacy of sonographic and computed tomo-graphic (CT) techniques in differentiation and monitoring of apical cysts and granulomas.METHODOLOGY: Ten patients having large periapical lesions (~18x15x30 mm) in maxillary and mandibular jaws were selected and consented to the study. Provisional preoperative diagnosis was made based on historical, clinical and radiographic (periapical and panoram-ic) features by two endodontists. Preoperative ultrasound and Color Doppler (CD) evaluations were made by examining the size, echo char-acteristics and vascular supply of the lesion by one radiologist and one endodontist to classify it as hypo- versus hyperechoic area. Root canal treatments were performed in all cases when the symptoms (pain, swelling and pus) were resolved. Otherwise, endodontic treatments were combined with enucleation and/or surgical curettage of the le-sions. Differential diagnosis was made using histopathologic fi ndings supported with CT scans and echo characteristics.RESULTS: Seven of the periapical lesions had true cysts according to sonographic and CT evaluations which were confi rmed with histo-pathologic fi ndings accepted as gold standard. Three of the periapi-cal lesions diagnosed as granuloma were treated nonsurgically. One year monitoring results showed that healing process was completed or continuing. CONCLUSION: CT scan and ultrasound with CD can provide a diag-nostic tool in differentiation and monitoring of apical cysts and gran-ulomas.

15.50 – 16.10

Treatment decision between endodontically treated tooth

and dental implantC. Setzer FrankUniversity of Pennsylvania, School of Dental Medicine, Philadelphia, PA, USA

Abstract

Many practitioners face the decision of when to treat a tooth end-odontically or when to extract it and place an implant. This lecture reviews evidence-based research on the long-term success and survival of implants and endodontically treated teeth and discusses treatment decisions made by different dental specialties and the sci-entifi c reasoning behind it. At conclusion, participants should be able to compare endodontic and implant treatment options in regard to success and survival rates, make an educated decision whether to endodontically treat a tooth or extract and replace it with an implant and understand the importance of an interdisciplinary treatment planning approach.



ROOM ELLISSETHURSDAY, 15TH SEPTEMBER 2011

11.00 / 19.00


Chairperson: Emanuele Ambu

11.00 – 11.20

A novel and modern approach to treat curved root canals Enrico Cassai, Simone Vaccari University School of Dentistry, Ferrara, Italy

Abstract

One of the primary goals of root canal treatment is to completely clean and shape the root canal system. The path of the origin root canal should be maintained and the dentine on the root canal wall should be cut circumferentially so that the outline of the prepared root canal wall still refl ects the original outline.Modern engine-driven rotary root canal instruments made of nick-el-titanium are expected to allow the preparation of even severely curved root canals in a safe and time-saving manner. Procedural er-rors such as loss of working lenght, straightening of the root canal, strip perforation, funnel shaped enlargement of the apical canal seg-ment as well as instrument separation need to be avoided.The aim of this oral comunications is to suggest by means of original 3d videos and clinical cases a practical method to shape correctly and safely curved root canals.

11.20 – 11.40

Root canals deformation with PathFile® systemAlberto García Barbero, Ferrero Márquez Patricia, Carlos Prados Hernández, Ernesto García BarberoMaster of Endodontics, Faculty of Dentistry, Complutense University, Madrid, Spain

Abstract

INTRODUCTION: the endodontic GlidePath is a smooth radicular prep-aration from canal orifi ce to foraminal constriction. It must be previ-ously done to rotary root canal instrumentation. This procedure is usu-ally done by hand instruments, but recently new nickel-titanium rotary instrumentation system (PathFile®. Dentsply-Maillefer. Ballaigues-Switzerland ) has been designed to perform GlidePath mechanically .AIM: the aim of this study is to evaluate the deformation of root canal curvatures when performing glide path using PathFile.MATERIALS AND METHODS: twenty extracted human teeth with varying degrees of root curvatures were selected. Canal permeability was verfi ed with a #10 K fi le reaching the apical foramen. Root canals were prepared with PathFile® system according to manufacturers instructions. Radiographs of the root canals taken before and after root canal preparation were analyzed by using AutoCAD 2010 to mea-sure the angle of curvature. Stereoscopic images of apical foramenes taken also before and after root canal preparation with PathFile sys-tem were analyzed by using Image Tool to measure the area of the apical formen. Oneway ANOVA test was used for statistical analysis.RESULTS: anova test showed statistically signifi cant variations in the angles of curvatures and also in the surfaces (p < 0,05)CONCLUSIONS: according to this study, PathFile system produces root canal deformation.

11.40 – 12.00

Root canal shaping without manual instruments: a real

possibility or just a dream? Alessandra D’Agostino, Giuseppe CantatoreUniversity of Verona Department of Endodontics, Ass. Prof. G. Cantatore

Abstract

Many studies shows that both manual prefl aring and glide path with K-fi les signifi cantly reduces the risk of rotary fi le separation; manul prefl aring however can be diffi cult and create ledges or apical trans-portation, mainly in curved root canal.Recently, new rotary NiTi fi les, designed for mechanical prefl aring and glide path have been introduced. Several research studies sup-port the mechanical glide-path because of the lower risk of compli-cations and a better maintainance of the root canal anatomy. Fur-thermore they facilitate the penetration of NiTi greater taper fi les. In another investigations rotary fi les used for glide path facilitated the penetration of the irrigating salutions. The only drawback of this fi les is the requirement of an initial negotiation with a manual K-fi le # 8 or 10. In this study we evaluated the possibility and risk of using these new fi les without any manual negotiation thus obtaining an instrumenta-tion sequence exclusively based on mechanical instruments.

12.00 – 12.20

The challenge of the necrotic open apexChaniotis AntonisClinical Instructor Department of Endodontics, University of Athens, Greece

Abstract

Root canal treatment of permanent pulpless teeth with open apices poses great clinical challenges. For many years the apexifi cation pro-cedure was the treatment of choice. Despite the popularity of this technique inherent disadvantages existed; Variability of treatment time, unpredictability of apical closure, diffi culty in patient follow up, susceptibility to fracture and reinfection were the main disadvan-tages of this procedure. All these disadvantages made the scientifi c community continue the search for procedures and materials that may allow for continued apical closure in teeth with immature api-ces. Although the research for revascularisation procedures of the necrotic open apex is very promising, MTA apical plug technique is still considered a good alternative treatment procedure. This presen-tation is designed to guide the clinician through the MTA plug and revascularisation procedures and to provide tips and hints for the successful management of challenging open apex cases.

12.20 – 12.40

Canal transportation of Ni-Ti rotary pathfi le-protaper

with a new protocol in simulated S-shaped canals Baser Elif Delve, M Gerek, MB Kayahan, K Mohseni, H Sunay, G Bay Yeditepe University Faculty of Dentistry, Istanbul, TurkeyPrivate Practice limited to Endodontics, Istanbul, Turkey

Abstract

Ni-Ti rotary instruments were introduced to improve root canal prep-aration. In curved canals preparation becomes more complicated and for all preparation techniques there is a risk of canal transportation. Pathfi le rotary Ni-Ti instruments (Dentsply-Maillefer) have been in-troduced to be used in combination with the ProTaper instruments (Dentsply-Maillefer). The aim of this study is to compare the root canal transportation with PathFile-ProTaper(PP), PathFile-ProTaper new protocol and stainless steel K-fi les.45 ISO 15, 0.02 taper S-shaped Endo Training Blocks were divided randomly into 3 groups of 15 each and prepared as follows: Group I: PathFile-Protaper, Group II: Pathfi le-Protaper new protocol (fewer instruments), Group III: manual fl aring with K-Files. The amount of






16

transportation was assessed by scanning the blocks consistently un-der the same conditions before and after preparation and superim-posed the images with an imaging software (Photoshop). Right and left cutting increments of root canals were measured in each of 12 traced levels along the root canal length.The results of this study show that manual fl aring caused signifi -cantly more transportation than the two Pathfi le-Protaper systems. There were no signifi cant differences regarding to transportation be-tween the classic and new Pathfi le-Protaper protocol.Based on the conditions of this study it may be indicated that new Pathfi le-Protaper protocol transports the canal similar with classic Pathfi le-Protaper protocol. This means that similar preparation can be made with fewer instruments.

13.00/ 14.30 LUNCH

14.30 / 16.30

Chairperson: Augusto Malentacca

14.30 – 14.50

The use of cone beam computed tomography and digital

periapical radiographs to diagnose root perforations H Shemesh, Roberto Cristescu, PR Wesselink, M-K Wu ACTA, Amsterdam, The Netherlands

Abstract

Introduction: The aim of this study was to compare the sensitivity and specifi city of cone beam computed tomography (CBCT) scans and digital periapical radiographs (PR) in detecting strip and root perfo-rations after root canal treatment in mandibular molars. Methods: Forty fi ve curved mesial roots were endodontically pre-pared. 15 roots were perforated in the mesio lingual (ML) canal by in-serting a rotary fi le through the canal curvature penetrating the root surface (“root perforation”) and 15 roots were perforated with a gates glidden drill in the axial aspect of the canal (“strip perforation”). 15 roots were not perforated. All mesial roots were fi lled with gutta per-cha and AH26. Teeth were then placed in human mandibles. PR from two angulations and CBCT scans were evaluated by two observers. The sensitivity and specifi city of both methods to diagnose perfora-tions were calculated. Results: The Sensitivity and specifi city of CBCT in detection of strip perforations were 0.50 and 0.97 respectively and by two-angled PR 0.13 and 0.97. For detection of root perforations, the sensitivity and specifi city of CBCT were 0.86 and 0.70 respectively and for PR 0.66 and 0.90. The difference between PR and CBCT scans in detecting strip perforations was signifi cant (chi square test, p<0.05).Conclusions: The risk to misdiagnose strip perforations was high with both methods, but CBCT showed a signifi cant higher sensitivity than PR. There was no signifi cant difference between the methods for the detection of root perforations.

14.50 – 15.10

Dynamics of periapical lesions in endodontically treated

teeth left without intervention: a longitudinal study I Tsesis, Tomer Goldberger, E Rosen, M Seifan, A Tamse Department of Endodontology, Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University,Tel Aviv, IsraelMaccabident, Tel Aviv, Israel

AbstractA high prevalence of periapical lesions is commonly reported in cross-sectional studies. However such studies do not provide infor-mation about the dynamics of periapical lesion associated with end-odontically treated teeth and whether intervention is needed. The present study was designed to retrospectively evaluate the long term dynamics of periapical lesions associated with endodontically treated teeth that were left without intervention and the effect of pos-sible infl uencing factors.

A total of 720 periapical status surveys of patients that were accepted for treatment in a public dental clinic between years 2007-2009 were retrospectively evaluated for the presence of periapical lesion asso-ciated with endodontically treated teeth. Two consecutive periapical surveys of each patient with at least 4 years interval were examined. The dynamics of the periapical lesions was evaluated based on the PAI score changes. Logistic regression with GEE was used to evalu-ate the infl uence of various factors with “worsening of lesion” as the dependent variable. The study cohort consisted of 74 patients with a total of 200 endodon-tically treated teeth with periapical lesion that answered the inclu-sion criteria. A hundred and three lesions (51.5%) worsened, 40 le-sions (20%) improved and 57 lesions (28.5%) remained un-changed. Poor root canal fi lling quality and poor restoration were found to signifi cantly affect the worsening of periapical lesions over time. (P<0.05). Age, gender, and the presence of a post had no statistically signifi cant infl uence (p>0.05). Thus, endodontic retreatment should be recommended in cases with poor root canal quality and/or poor restorations.

15.10 – 15.30

Endodontic treatment of periapical lesions: two visits

evidence based approachEkaterina BotevaDepartment of Conservative Dentistry, Faculty of Dental Medicine, Sofi a, Bulgaria

Abstract

Although the advances in endodontics have been drastical in the last decade, at today prognostic studies of periapical lesions are rare. The aim of the present study is to follow up for one year the results of two steps treatment of patients with Chronic Apical Periodontitis. In the exclusion criteria were root apical resorptions, long history of ex-acerbations, patients with diabetes, neoplasms and cardio-vascular diseases. All lesions (n=91) were treated in Sofi a Dental School and were subjected to EB examination, for decision making and treat-ment planning and at least 3 x-rays during the treatment. Some patients previously received dental treatment, all had diagnostic x-rays of chronic periapical lesions, and some had typical periodonti-tis manifested symptoms. The fi rst visit includes manual root canal instrumentation using Step-down technique. The irrigating solutions were 0.5% NaOCl and hydrogen peroxide. The second visit takes place 7-14 days later and the teeth were medicated with different dressing, according to the level of suppuration. During the second visit the root canal and the apical stop were preparated with the Step-back technique. The level and dimension of the preparation of each root canal depends on the amount of infected dentin and individual anatomy of each tooth. Special care was taken for the drying. The method of obturation depends on evidences like: size and location of the periapical lesions, level of suppuration during the treatment, etc. No posts or crowns were fi xed on the respective teeth for 3 months. X-ray controls were taken after 3, 6 months and 1 year. In conclusion the high rate of success of the endodontic treatment of periapical le-sions did not depends on the irrigation and chemical composition of the root canal fi lling, age or sex of the patients. It depends on good manual instrumentation and adequate fi lling method.

15.30 – 15.50

The fi ve year survival and success rate of endodontic

treatments performed by undergraduate studentsMarie Georgelin-Gurgel, F Diemer, L Fourcade, M Hennequin, L Van Der Sluis University School of Dentistry, Toulouse, France

Abstract

The goal of this study was to evaluate the fi ve years survival and suc-cess rate of endodontic treatments performed by undergraduate stu-dents in a French University Hospital of dentistry. Furthermore, the infl uence of some clinical factors were evaluated.



Method and materials: The records of 125 patients which were end-odontically treated in the dental hospital in 2005 by undergraduate students were collected in 2010. This resulted in 180 treatments in 125 patients who were contacted for a recall appointment. The recall rate was 32% and 65 treatments could be included for the evaluation. During the evaluation, a clinical exam was performed and a radio-graph was taken. The radiographs taken directly after the treatment and fi ve year later were evaluated using the PAI score index.Results: the survival rate was 89% and the success rate was 72%. The absence of coronal sealing, the number of treatment sessions, maxillary localisation, the number of canals and periapical pathol-ogy, negatively infl uenced the survival and success rate.Conclusion: we concluded that the survival and success rate of the endodontic treatment performed in an undergraduate student hospi-tal is comparable to the reported outcome studies and is negatively infl uenced by the absence of coronal sealing, the number of treat-ment sessions, maxillary localisation, the number of canals and peri-apical pathology.We also found that the survival rate was higher than success rate.

15.50 – 16.10

Study of the internal anatomy of upper molars different

from populations representing 4 continentsTopham Alvarez Guillermo, Meritxell Benages, Fernando Duran-Sindreu, Rufi no Bueno, Miguel RoigSpain

Abstract

Study of the internal anatomy of the fi rst and second molars by clear-ing technique in 7 population groups. After a literature review we found no previous studies involving popu-lations from 4 continents. The population groups to study are the following: Barcelona and Gran Canaria, Spain / London, UK (EUROPE) / sub-Saharan, black Africa / Nouadhibou, Mauritania (AFRICA) / Andhra Pradesh, India (ASIA) / Guatemala City, Guatemala (AMERICA). Our objetive is to describe the internal anatomy of the different roots of upper molars, according to the Vertucci classifi cation of each of the populations and compare the results. The teeth were collected by colleagues who live in the countries of origin or go to volunteer. At the time of extraction they were classifi ed into 1st and 2nd molars. The teeth were disinfected, stored in wet condition and then delivered to us. We performed the cameral opening and classify them according to the number of canals located. We applied the protocol technique of clarifi cation, used by the Authors in previous studies. Once the clarifi cation process was completed the specimens are injected with India ink and photographed. Then they are sorted according to the Vertucci classifi cation and descriptive statistics was performed. In the results we observed that the most common anatomy is different for each population. The conclusion we get from this study is that depending on the origin of the patient, anatomical variations could be predicted.

16.10 – 16.30

A new method for diagnosis of atypical root resorptions

and anatomical abnormalities using CBCT enhanced by

3D video imagingKfi r Anda, Laittner Amnon, Metzger ZviDepartments of Endodontology, Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, IsraelRadiographic institute “Panorama”, Nahariya, Israel

Abstract

CBCT enhanced by 3D video imaging is a new way to analyze com-plicated endodontic cases in order to facilitate their diagnosis and treatment. Its application will be demonstrated on cases of multiple idiopatic internal resorption and complex cases of dens invaginatus.Internal resorption with a classical radiographic appearance is easily

diagnosed and may be predictably treated. External resorption, on the other hand, has different ethiology and calls for completely dif-ferent treatment. The case to be presented had atypical radiographic appearance that resembled external resorption. CBCT enhanced by video imaging was used to determine the nature of the lesions. Indi-vidual CBCT images were non-conclusive but the video imaging al-lowed to establish that the resorption cavities were internal with no communication to the surrounding periodontal ligament and bone. When pulp chambers were opened, this diagnosis was clinically veri-fi ed.Complicated cases of dens invaginatus will be presented in which periapical radiographs gave no clue as to the 3D structure of the tooth and as to the best way to approach these cases. CBCT enhanced by 3D video imaging allowed for clear understanding of the different pulp compartments in these teeth and their relation to the periapi-cal lesion, thus avoiding the trial-and-error approach that otherwise would have been necessary in these cases.The CBCT enhanced by 3D video imaging is proposed as an extremely useful tool for endodontic diagnosis as well as for communication with the patient.


17.00 / 19.00

Chairperson: Antonio Bonaccorso

17.00 – 17.20

Prognosis of endodontic microsurgery: an evidence

based approach R Kohli MeetuUniversity of Pennsylvania, School of Dental Medicine, Philadelphia, PA, USA

Abstract

Endodontic surgery has evolved into microsurgery. Introduction of the microscope, ultrasonics, microinstruments and more biologically acceptable root-end fi lling materials have changed the technique signifi cantly. It is now a precise and methodically conducted proce-dure. However, when the prognostic data for endodontic surgery is reviewed, there is a tendency to combine the results from traditional and modern techniques together - with disregard to the effect that microsurgical techniques have on prognosis. On an evidence base, this presentation reviews the literature describing surgical prognosis and elucidates that microsurgical techniques have in fact improved the end result and provide an excellent treatment alternative with predictable outcome.

17.20 – 17.40

In vivo study: location and negotiation of the second

mesiobuccal canal of maxillary second molars Davide MancinoFrance

AbstractThe aim of this in vivo study was to determine the canal morphol-ogy of maxillary second molars, with a particular attention to the presence of second mesiobuccal canals (MB2). If the failure of end-odontic therapy can be due to lack of treatment of few millimeters of endodontic tissues, the non-location of a whole canal system can prejudice the prognosis of an endodontic treatment. A clinical study was conducted on 103 successive cases of root-canal therapy on maxillary second molars, during a period of 18 months. The author used surgical headlamps and dental loupes. Access preparations were modifi ed to a rhomboid shape for all maxillary second molars. If the MB2 wasn’t immediately detected, the portion of pulpal fl oor between the MB1 and the palatal canal was searched with an ultra-






18

sonic tip. The results demonstrate that 67% of the treated molars showed the presence of MB2. In 41.3% the mesiobuccal root had a canal confi guration of Weine’s type II. The high incidence of the MB2 in maxillary second molars leads to the conclusion that this element should be considered as a four canal tooth. Actually, the absence of the MB2 is an exception. Clinician should take the necessary time to locate and negotiate the MB2, but above all, he has to be convinced of its presence. Once the MB2 is located, it should be shaped and pre-pared in a conservative way, to avoid any risk of fracture or stripping. So the MB2 should be shaped with a taper no larger than 06, and for the Weine’s type III, it should be prepared till the confl uence with the MB1. Moreover, this study describes possible MB2 locations and sug-gests some methods to detect the MB2 in maxillary second molars.

17.40 – 18.00

Assessment by cone beam computed tomography scans

of the effectiveness of endodontic treatment ME Metska, PR Wesselink, Rifat Ozok Academic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, The Netherlands

Abstract

The aim of this study was to assess the effectiveness of root canal (re)treatment, with the use of cone beam computed tomography (CBCT) scans at the fi rst year of recall. The study protocol was approved by the medical ethics committee at the Medical Centre of the Vrije University in Amsterdam (METc VUmc 207/265).Fifty teeth out of fi fty healthy individuals referred for diagnosis and (re)treatment in the Postgraduate Endodontology Clinic of ACTA, partici-pated in the study. All cases were diagnosed with apical periodontitis. The group of patients was recalled one year after (re)treatment. The radiographic examination before the endodontic (re)treatment and at the one-year recall comprised of a digital intraoral periapical radiograph (phosphor-plates, Digora, Tuusula, Finland) and a CBCT scan (NewTom 3G, QR SLR, Verona, Italy). The variable examined was the absence or presence, and, in the latter case, the size of periapi-cal lesion. Two “case-blinded” and calibrated observers assessed all images, which were presented in a random order, to avoid expecta-tion bias. Each image was examined twice in different sessions by each observer. When the lesion, at the time of the recall, was absent or reduced in size, the endodontic (re)treatment was categorized as effective. In cases where the size of the lesion increased or did not change in size, the endodontic treatment was categorized as ineffec-tive or uncertain, respectively.More periapical lesions were detected with the CBCT as compared to periapical radiographs. The use of the CBCT is a new method for evaluating the effectiveness of the endodontic (re)treatment and put-ting under discussion the present criteria.

18.00 – 18.20

Patient referred to Endodontist: diagnostic and operative

concerns Maria Veronica Orsi Assistant Professor of Endodontics at the University of Bologna Dental School, in the Master of Prosthodontics (Prof. R. Scotti) and in the Master of Endodontics (Prof. C. Prati), Italy

Abstract

Thanks to new technology and modern instruments, today the out-come of Endodontic Treatments have achieved high success rate and most general dentists can perform root canal treatment with easier techniques and less operative time. Still when some cases appears to be more complex, for diagnostic and operative reasons, general dentists may decide to referr patients to Endodontist, in order to achieve a more predictable success. Sometimes it can be diffi cult to check earlier tooth-cracks or to un-

derstand the origin of pain. A misunderstanding in diagnosis leads to an erroneous treatment planning.Clinically main diffi culties usually happen during the procedure of “open access cavity” in front of aberrant anatomy or calcifi cations that can avoid the correct location of the original root canal system. If the access cavity is open in defect, not all the existing canals will be found; if the access cavity is open in excess, this will lead to un-necessary removal of tooth structure and to the risk of iatrogenic perforations. During retreatments the main concern is linked to the possibility to remove previous obstacles in order to reach the original anatomy and to have the possibility to clean, shape and fi ll all the root canal system.The Endodontist, thanks to the use of microscope together with the new endodontic devices, constantly deals with treatment of complex endodontic cases, in order to fi nd canals previously not discovered, to remove metal or fi ber post and broken instruments inside the root canal system, to seal iatrogenic perforations and wide open apex with MTA. During this lecture many different clinical cases will be presented.

18.20 – 18.40

Reciproc (VDW, Germany) in clinical use in molars: the

relationship between preparation form and disinfection Monica Daniela Chiperi Germany

Abstract

Aim: To measure the depth of irrigation needle penetration in root canals of molars in clinical practice, in adult patients.Methodology: One hundred and eighty root canals in upper and lower fi rst and second molars with intact and patent apices and no previ-ous root canal treatment were included in this study. After perform-ing a standard endodontic access cavity, the working length was established using a ISO size 10 fi le and an apex locator. Root canal instrumentation was performed with a single instrument, the Re-ciproc (VDW, Germany) ISO size 25 taper.08 connected to the VDW.Silver Reciproc motor, in a reciprocating movement with light api-cal pressure. When resistance was encountered, the instrument was pulled out and the fl utes were cleaned of debris. This was repeated until working length was reached. The irrigation was performed with warm sodium hypochlorite solution in a hand syringe with an irriga-tion needle gauge 27 (Transcoject, Germany). The depth of needle penetration was determined with a silicone rubber stopp and re-corded. The data were statistically analysed and compared to data obtained after instrumenting root canals of molars with the Mtwo system (VDW, Germany).Results: The depth of the penetration of the irrigation needle was suffi cient in large root canals with a small degree of curvature. Nev-ertheless, in root canals with a higher degree of curvature, the irri-gation needle didn’t reach the apical third, which shows the need of greater taper preparation.Conclusion: The method allows control of penetration depth of the irrigating solution for thorough disinfection of the apical third and shows the need of larger apical preparation with suffi cient taper.

18.40 – 19.00

Successful use of high frequency ozone generator and

bio-oxidative therapy in endo-restorative treatmentPavelic BozidarDepartment of Endodontics and Restorative Dentistry School of Dental Medicine, University of Zagreb, Croatia

Abstract

Over the time bio-oxidative and ozone therapy has undergone many stages, from autohaemotherapy, through insuffl ations, ozonized wa-ter, ozone saunas and tents, to hypodermic injections. Technologies have ranged from most primitive ozone generators, to more modern UV rays or cold plasma based.



Ozone is a thermodynamically highly instable compound which, de-pending on system conditions such as temperature and pressure, decomposes to pure oxygen with a short half-life. There are several known effects of ozone on human body, such as antimicrobial (bacte-ricidal, virucidal, and fungicidal), immunostimulating and biosynthet-ic (activation of the metabolism of carbohydrates, proteins, lipids). Bio-oxidative therapy is a non-medicamentous method of therapeu-tic action proved to be effective in the treatment of different kind of infl ammatory and degenerative diseases. The highfreqency generator Ozonyx (Biozonix, München, Germany), produces a high frequency electrical fi eld (resonant frequency 30-50kHz, impuls frequency 470 - 1050Hz, trigger voltage 3-18kV, cur-rent 100 μA) on the tip of the plasma probe when it gets in contact with the human body. Ozone concentrations produced by the high-freqency generator Ozonyx for use in dental ozone therapy vary from 0 - 2,1 mcg/s (depending on the design of the plasma probe and cho-sen intensity), which allows a wide range of applications in different therapies.The antibacterial, anti-infl ammatory and bio-stimulative effect of bio-oxidative therapy may be used in the management of diffferent den-tal indications such as caries, root canal treatment, wound healing, gingtivitis, periodontitis, periimplantitis, viral and fungal infections. When the correct dose has been established, ozone can be used as a useful therapeutic agent. The extremely rapid antimicrobial activity is fundamental for the effective therapy. The purpose of this lecture is to present a successful clinical use of a high frequency ozone genera-tor and bio-oxidative therapy in endo-restorative treatment.

ROOM ELLISSEFRIDAY, 16TH SEPTEMBER 2011

8.30 / 18.40

8.30/10.30

Chairperson: Luc van der Sluis

8.30 – 8.50

Study of the extrusion of irrigant fl uid based on the

instrumentation method Ana Antoranz Pereda, Carmen Pellejero Hinojosa, Ernesto García Barbero, Daniel Martín GonzálezSpain

Abstract

Introduction: Sodium hypochlorite is the most commonly used end-odontic irrigant because of its antimicrobial and tissue-dissolving activity. Due to his cytotoxic capacity, it shall only be used under the most comprehensive precautionary measures. The presence of so-dium hypochlorite outside of the root canals can cause soft tissue damage and may even compromise the patient’s health.Aims: To assess the volume of sodium hypochlorite extruded apically during root canal preparation by the instrumentation method used. Determine whether the working length, time of instrumentation and the amount of irrigant used affects the amount of irrigation fl uid ex-travasation.Material and method: 150 extracted human tooth roots were ran-domly assigned to 5 groups, 30 teeth each, according to the study inclusion criteria. The instrumentation systems used were: manual technique (group 1), manual glyde path and Protaper® (group 2), Pathfi le® and Protaper® (group 3), Mtwo® (group 4) and Reciproc® One File Endo (group 5). The roots were placed in a silicone block so that the apexes were in contact with an absorbent paper. The ir-rigation protocol was established depending on the instrumentation method. The irrigant used was a mixture of sodium hypochlorite with China ink. The dark spots caused by the extrusion of irrigating fl uid were studied using the Image Tool® 3.00 and statistically analyzed using the SAS 9.1® program.Results: With the Kruskal-Wallis test differences were statistically signifi cant (p<0,05) between groups 1 and 2, between groups 1 and 5 and between groups 2 and 3.Conclusions: In our study, all tested systems produce extrusion of the irrigation fl uid. The manual technique is the method that pro-duces the greatest extrusion of irrigation fl uid. Working length, time of instrumentation and the amount of irrigation fl uid do not infl uence signifi cantly the area of fl uid extravasation.

8.50 – 9.10

Photodynamic therapy as an alternative for root canal

disinfectionAdriano Azaripour, M Hassan, M Foersch, I Willershausen, P Brandstätter, I Jacobi, M PietschUniversity School of Dentistry, Mainz, Germany

Abstract

Objectives: The aim of this in vitro study was to evaluate the antimi-crobial effect of Photodynamic therapy (PDT), a light activated disin-fection system (LAD) and three different commonly used irrigation solutions (NaOCl, chlorhexidine, H2O2) on root canals infected either with Enterococcus faecalis or Staphylococcus aureus.Methods: Extracted single rooted human teeth were endodontically instrumented and autoclaved, then inoculated with either Enterococ-cus faecalis (ATCC 6057) or Staphylococcus aureus (ATCC 6538) for 24 hours. The teeth were divided in 8 groups of treatment for each






20

bacterial species (n=2 x 8 x 20): (a) control group (untreated), (b) PDT group treated with methylen blue and soft laser irradiation (l=670 nm) for 60 seconds, (c) LAD group treated with toluidin blue and LED light irradiation (l=670 nm) for 60 seconds, (d) 5 ml NaOCl solu-tion (1%), (e) 5 ml NaOCl solution (3%), (f) 5 ml clorhexidine solution (0.12%), (g) 5 ml chlorhexidine solution (2%) and (h) 5 ml H2O2solu-tion (3%). Subsequently each tooth was placed in sodium chloride solution (0.9%), sonicated (2 min) and shaked (1 min). In addition the collective solutions were cultivated in culture dishes for 24 hours. Statistical analysis was carried out using the Mann-Whitney-U-Test and p-values<0.001 were considered as signifi cant.Results: The control group showed an average of 106 CFU/ml for both bacterial species. The bacterial reduction with regard to the treated groups was as follows: for E. faecalis: b=98.18%, c=88.97%, d=99.99%, e=100%, f=99.52%, g=99.71% and h=99.99% and for S. au-reus: b=95.01%, c=93.40%, d=99.99%, e=99.99%, f=99.05%, g=99.99% and h=99.43%.Conclusion: The PDT and LAD could be developed as adjuvant meth-od to conventional endodontic treatment. NaOCl solution of 3% con-centration had the highest antimicrobial effect with reduction of both bacteria species. Therefore it can be regarded as the golden standard for root canal irrigation during endodontic treatment.

9.10 – 9.30

SEM study on the effectiveness of a canal brush on the

cleanliness of the root canalsEleni Protogerou, Ioanna Arvaniti, Ioannis S. Vlachos, Marouan KhabbazPostgraduate student in Endodontics, School of Dentistry, University of Athens EndodontistLecturer, Laboratory for Experimental Surgery and Surgical Research “N.S. Christeas”, Medical School, University of AthensAssociate professor in Endodontics, School of Dentistry, University of Athens

Abstract

Background: Although many methods have been advocated for re-moving debris and smear layer (SL), none has proved effi cient enough for this purpose. Aim: The aim of this in vitro study was to assess the effectiveness of a Canalbrush (Coltene/ Whaledent GmbH_Co. KG, Germany) on the removal of debris and SL from the instrumented root canals.Materials & Methods: 44 single- rooted lower incisors were treated via a standard chemomechanical preparation schema and separated into three groups where the fi nal irrigation regime included: Group A- irrigation with 10ml sodium hypochlorite and activation with a canal brush (n=14), group B- irrigation with 10 ml of EDTA for 3 minutes, 10 ml of NaOCl and canal brush (n=15), group C) EDTA and NaOCl, 10 ml of each solution (control group, n=15). Afterwards, root canal surfaces were observed under the SEM, by three independent examiners using a specifi c scoring system 1 to 4 where score 1 was the best.Results: Group C exhibited the lowest mean debris (1.07±0.21) and SL levels (2.9±0.86) and Group A the highest (1.6 ± 0.66 and 4.0 ± 0.21 respectively). All differences between the three groups were statisti-cally signifi cant.In the apical third, Group C exhibited signifi cantly lower debris and SL levels (1.02 ± 0.07 and 3.6 ± 0.48 respectively) than the other two groups whilst Groups A and B didn’t differ signifi cantly.In the middle third, Group C and B exhibited the same measurements for the debris level which were signifi cantly lower than that of group A. For the SL measurements, group C exhibited signifi cantly lower levels than the other two groups.In the coronal third, Group C exhibited the lowest debris and SL levels than groups A and B.Conclusions: Under the condition of this investigation, it seems that this specifi c canal brush is unable to remove debris and smear layer from the instrumented root canals.

9.30 – 9.50

Passive ultrasonic irrigation of the root canal system:

safety and effi cacyDavid E. JaramilloAssistant Professor of EndodonticsDirector of Endodontics International Dentist Program Clinic Director of EndodonticsLoma Linda University School of Dentistry

AbstractThis lecture will discuss and compare the safety and effi cacy of pas-sive ultrasonic irrigation as well as other commonly used irrigation techniques. It is widely accepted that the root canal morphology is highly complex. It is composed of oval shape canals, isthmuses, fi ns and apical ramifi cations. These canal irregularities are challenging areas to thoroughly clean and disinfect. The use of CBCT technology and SEM microscopy was used to compare the safety and effi cacy of the various irrigation techniques presented.At conclusion, participants should be able to:1. Describe the benefi ts of passive ultrasonic irrigation.2. Discuss the relationship between ultrasonic tip depth penetration and irrigant extrusion into periapical tissues.3. List the advantages and disadvantages of current irrigation tech-niques.

9.50 – 10.10

SEM Study of Root Canal Debridement with the EndoAc-

tivatorClauder Thomas, Baumann MA, Termaat SHMPrivate practice, Hamburg, GermanyDepartment for Operative Dentistry and Periodontology, University of Cologne, Cologne, Germany

AbstractAim To determine the cleaning effi cacy by irrigation with support of the new sonic device EndoActivator (Dentsply Maillefer, CH). The hy-pothesis was that sonic irrigation results in less debris and smear layer on canal walls.Methodology Fifty mesial roots of human mandibular teeth were in-strumented using ProTaper up to F4 (#40 .06). Irrigation after each instrument differed between the fi ve groups (n=10). Group 1: distilled water (2ml), group 2: NaOCl after each instrument (2.5%, 2ml), group 3: NaOCl after each instrument (2.5%, 2ml) followed by EDTA (17%, 5ml) for one minute and terminal rinse with NaOCl (2.5%, 2ml), group 4: same protocol as group 3 with additional 30 seconds sonic activation of NaOCl (2.5%, 2.5 ml) by EndoActivator (tip blue: #35 .04) and group 5: same protocol as group 3 with additional 30 seconds sonic activation of EDTA (17%, 2.5ml) by EndoActivator (tip blue: #35 .04). Roots were split and SEM examination was performed. Debris and smear layer of root canal surfaces were scored for coronal, middle and apical thirds. Data were statistically analyzed using Mann-Whitney test.Results Less debris and smear layer (p>.05) was found in groups 3, 4 and 5 compared to control groups (1 and 2). While coronal and middle thirds showed less debris and smear layer than the apical third in group 3, enhancement of cleanliness even in the apical third obvi-ously was related to sonic activation of 17% EDTA as well as 2.5% NaOCl by EndoActivator for 30 seconds (group 4 and 5). Conclusion EndoActivator irrigation of EDTA or NaOCl for 30 seconds improved root canal debridement in all regions of the root canal es-pecially in the apical third.

10.10 – 10.30

Infl uence of sodium hypochlorite in the dentine´s

resistence fracture Garcia Barbero E, Gomez F, Novoa Valls AsahiComplutense University of Madrid, Madrid, Spain

AbstractAIM: The aim of this study was to evaluate the fracture´s resistance of dentin using sodium hypochlorite at different times and concentra-



tions. INTRODUCTION: Sodium hypochlorite solution is used for irri-gation of the root canal. The sodium hypochlorite solutions have been used as endodontic irrigation technique for a long time and widely accepted in concentrations ranging between 2.5% and 6%. As an endodontic irrigant, is bactericidal, dissolved organic material, drag ditritus and lubricant. within their main disadvantagesis its toxicity. dentin contains about 22% organic material, mainly collagen type I, and which is attributed in large part responsible for the mechanical properties of it, which is why it believes may affect the fracture of dentin. MATERIALS AND METHODS: Fifty extracted permanent teeth were selected and preserved under saline solution. Their roots were cut into 1mm thick disks and aleatory separated in 7 groups of 30 teeth each. the control group was sumerged into saline solution and the rest into sodium hypochloride at different times (1h & 24h) and concentrations (2.5%,5%,5.5%) respectively. Each disc was subjected to compressive forces in a Hounsfi eld tensile machine at 5000 N com-pression strength and low speed 1mm/min. All data were statistically analyzed by ANOVA test. Results: There is statistically signifi cant difference p=<0.000001 be-tween the control group and each of the groups studied. Conclusion: Sodium hypochlorite signifi cantly infl uence the fracture resistance of dentin.


11.00 / 13.00

Chairperson: Francesco Somma

11.00 – 11.20

The effectiveness of enzymatic irrigation on the removal

of an endodontic stressed multi-species model biofi lm Sadia Niazi, D Clarke, T Do, SC Gilbert, F Foschi, F Mannocci, D Beighton Department of Conservative Dentistry, King’s College London Dental Institute at Guy’s King’s College and StThomas’ Hospital, KCL, London, UK; Department of Microbiology, Dental Institute, King’s College London, London, UK

Abstract

Aim: To establish a nutritionally stressed multi-species model bio-fi lm and to investigate the dynamics of biofi lm killing and disruption by trypsin and proteinase K with or without ultrasonic activation.Methodology: Stressed biofi lms comprising Propionibacterium acnes, Staphylococcus epidermidis, Actinomyces radicidentis, Strep-tococcus mitis and Enterococcus faecalis OMGS 3202 were grown on hydroxyapatite discs or on endodontically prepared single rooted teeth in modifi ed fl uid universal medium containing serum proteins. The ability of 1% trypsin and 1% proteinase K with or without ultra-sonic activation to kill and disrupt the biofi lm was determined.Positive control irrigants, 1% NaOCl and 0.2% w/v chlorhexidine glu-conate and an untreated control were also included. Each treatment was replicated fi ve times. The biofi lms were investigated using confo-cal laser scanning microscopy (CLSM) with LIVE/DEAD staining and quantitative microbial culture. Data were analysed using bioImage_L and SPSSPC (Ver 16.0).Results: Nutritional stress in the multi-species biofi lm was ap-parent as the medium pH became more alkaline (from 5.58±0.1 to 5.94±0.13), glucose was not present in the supernatant and serum proteins were degraded. The CLSM analysis showed a decrease in the percentage of viable bacteria at the surface level of biofi lm in re-sponse to nutritional starvation. Trypsin and proteinase K were ef-fective in biofi lm killing since their aerobic viable counts (6.69 ±0.13 and 6.60±0.02 respectively) were signifi cantly lower (p<0.01) than the control group (7.86±0.03) and chlorhexidine (7.72±0.05). NaOCl was the most effective agent (p<0.001). Moreover the percentages of mean biovolumes for dead populations with trypsin and proteinase K were 55% and 37%, signifi cantly less than the control group (p<0.05).

Ultrasonic activation signifi cantly improved the action of all irrigants (p<0.001), except for NaOCl.Conclusion: Proteinase K and trypsin can have a future in the clinical practice as endodontic irrigants for the treatment of both primary as well as refractory endodontic infections.

11.20 – 11.40

Effectiveness of Self-adjusting fi le on debridement when

used under different operation times Senem Yigit Ozer, O Guzel, S Kaya Turkey

AbstractAim: Debridement during root canal treatment is mandatory using the chemo-mechanical instrumentation and irrigation methods. This study evaluates the debridement capacity of Self-Adjusting File (SAF) system when used under different operation times.Methodology: Root canal preparations were performed in 30 man-dibular premolar teeth using the SAF with a continuous irrigation device (VATEA) in a closed system in which the apical foramen was sealed. The vibration mode was used for 5 min during the prepara-tion. Teeth were divided into three groups. In Group 1, 10 new SAF fi les were used for 4 minutes. In Group 2, the 4-min previously used SAF fi les were operated in the same manner. In Group 3, the 8-min previously used SAF fi les were operated. During SAF operation 1.3 % NaOCl and 1 % EDTA were used alternately with continuous irrigation in all groups. Debris and smear layer removal were evaluated under scanning electron microscope.Results: Non-used, 4-min pre-used, and 8-min pre-used SAF effi -ciently removed debris and smear layer in all thirds of the root ca-nals. There were no signifi cant difference among the groups in terms of debridement.Conclusions: When SAF is operated in root canals with continuous fl ow of irrigation it results in debris and smear-free canal walls even in the critical apical thirds within 12 minutes.

11.40 – 12.00

New approaches on root canal debridement: a SEM study B Ureyen Kaya, AD Kececi, Guldas H. Egemen, T Aktan Suleyman Demirel University, Faculty of Dentistry, Department of Endodontics, Isparta, TurkeySuleyman Demirel University, Faculty of Arts & Sciences, Department of Physics, Isparta, Turkey

AbstractAim. To evaluate debridement effi cacy of three new approaches -PUI (passive ultrasonic irrigation), MTAD, low temperature atmospheric pressure plasma (LTAPP)- and the conventional NaOCl+EDTA meth-od in root canal walls using scanning electronic microscopy (SEM). Methodology. Fifty-fi ve mandibular premolars were prepared to an apical size 40/.06 and divided randomly into fi ve different test (n=10) and one control (n=5) groups according to following irrigation proto-cols: NaOCl+EDTA; NaOCl with PUI; MTAD; MTAD with PUI; LTAPP, saline. Samples for SEM evaluation (×2000) were prepared by sec-tioning teeth longitudinally. Level of smear layer and debris removal on the samples were examined by two independent evaluators in a blinded manner with a 3-point scoring system on cervical, middle, and apical thirds. The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests to compare their overall effi ciency and that of on each third (P= 0.05). Results: There were signifi cant differences among the irrigation protocols both in smear (χ2=101.326, P=0.00) and debris scores (χ2=70.240, P= 0.00). NaOCl+EDTA irrigation was the most effective (21.1%) method for smear layer removal whereas MTAD was the most (42.2%) for debris removal. Smear and dentin scores showed signifi -cant differences among the irrigation protocols in all thirds (p<0.05). NaOCl+EDTA irrigation, the most effective method for smear layer removal, had the score”0” 26.7% in coronal, 23.3% in middle, 13.3%






22

in apical thirds. Debris removal with score”0” was obtained mostly following MTAD irrigation with or without PUI (50% in coronal, 33.3% in middle, 26.7% in apical thirds). Conclusion: In this study, conventional irrigation protocol (2.5% NaO-Cl+17% EDTA) was the most effective method for root canal debride-ment. The use of MTAD with PUI can be recommended as an alterna-tive irrigation method, whereas LTAPP needs further investigation. Keywords: MTAD, Passive Ultrasonic Irrigation, Low Temperature At-mospheric Pressure Plasma, SEM, smear.

12.00 – 12.20

SEM evaluation of smear layer removal using micro-

brushesSamuel Guez, Etienne MedioniUFR d’Odontologie de Nice, Département d’Odontologie Conservatrice-EndodontieUFR de Nice Sophia Antipolis. 24 avenue des diables bleus 06357 Nice cedex 4

AbstractIntroduction: Rotary endodontic instruments produce “smear layer”. Smear layer removal is essential to access to endodontic treatment success. However, the use of appropriate irrigant solution and agi-tation technique is required. Aim of the study : To evaluate the ef-fectiveness of CanalBrush® endodontic microbrush for smear layer removal compared to passive ultrasonic irrigation. Method : 20 sin-gle-rooted teeth are divided in 2 groups (A and B)and prepared using Race® NiTi rotary fi les. Final irrigation for group A is realized with 4 ml of a 2,5 % NaOCl ultrasonically agitated (1 mn)solution + 1 ml of 17 % EDTA solution similarly agitated. For group B, it is realized with 4 ml of 2,5 % NaOCl solution agitated with CanalBrush® on contra-angle at 600 rpm during 1 mn + 1 ml of 17 % EDTA solution identically agitated. The dentinal surface aspect are observed under scanning electron microscope (SEM x 500) by 3 different evaluators. Results: There is no statistically signifi cant difference when the 2 groups are globally compared (p > 0.05) and between the 3 evaluators. However, there is a signifi cant difference for the apical third: ultrasounds are better (p = 0.0113). When Intra-group comparisons are achieved, in the group A, there is a statiscally signifi cant difference between the coronal and apical thirds (p = 0.0343). In the group B, there is a sta-tistically signifi cant difference between the coronal and apical thirds (p = 0.0032) and between the middle and apical thirds (p = 0.0126). Conclusion : Irrigation using NaOCl and EDTA ultrasonically agitated is still the reference for smear layer removal.

12.20 – 12.40

Cleaning root canals: the role of low surface tension

irrigantsLuciano Giardino Italy

Abstract

The objective of endodontic therapy is to remove the infection and to eradicate the bacteria from the root canal system. Mechanical instru-mentation alone does not result in a bacteria-free root canal system and when the complex anatomy of the root canal system is consid-ered, this is not surprising. On the other hand, ex vivo and clinical evi-dence has shown that mechanical instrumentation leaves signifi cant portions of the root canal walls untouched. Considering the fact that current techniques of root canal instrumen-tation leave many areas of the root canal completely untouched by the instruments, an irrigation solution is required to aid in the de-bridement of the canals. Sodium hypochlorite (NaOCl) is the most commonly used root canal irrigation solution. It has both tissue-dis-solving and antimicrobial properties . Despite its excellent tissue-dis-solving and antimicrobial abilities, NaOCl possess some drawbacks. One of its major drawbacks is its high surface tension, which limits it penetration into canal irregularities and the depth of dentinal tu-bules. Adding surfactants to NaOCl can resolve this problem. For improvement of their effi cacy, root canal irrigants must be in con-

tact with the dentin walls and debris. The intimacy of this contact depends on the wettability of the irrigant on solid dentin, and this property of the liquid is strictly correlated to its surface tension. With the introduction of new antibacterial irrigants with lower surface ten-sion capable of penetrating deeply into dentinal tubules, root canals cleansing has become more effective.

12.40 – 13.00

Bactericidal effect of gaseous ozone and octenidine

dihydrochloride against Enterococcus faecalis: an ex vivo

study Unverdi Eldeniz Ayce , B Ozcopur, S Sevimay, A Kalayci Faculty of Dentistry, Selcuk University, Yuzuncu University and Ankara University, Konya, Van and Ankara, Turkey

Abstract

Aim: To evaluate antimicrobial activity of gaseous ozone (Healozone, KaVo, Germany) in comparison with octenidine dihydrochloride (Oc-tenisept®, Schülke&Mayr, Germany) as a new antiseptic solution, 5.25% sodium hypoclorite(NaOCL) (Caglayan Kimya, Turkey), 2% chlorhexidine (Cetrexidin-C, Imicryl, Turkey) and 0.9% saline (I.E. Uragay, Turkey) in experimentally infected root canals. Methodology: Hundred extracted human-teeth were decoronat-ed, sterilized, infected with standardized E. faecalis suspension (OD600=0.5) and divided into three experimental and two control groups (n=20) and irrigated as follows; Group 1: gaseous ozone, Group 2: 2% chlorhexidine, Group 3: octenidine dihydrochloride, Group 4: 5.25% NaOCL (negative control) and Group 5: saline group (positive control). Sterile paper points were used to sample bacteria from the canals and carried to vials containing 5mL of brain heart (BH) infusion broth. After 24 h, 300μL broth transferred to 96-well plate to measure turbidity. Afterwards, dentine samples were ob-tained with gates-glidden burs (# 3, 4, and 5) from inner canal-lumen and transferred to vials containing phosphate buffered saline (PBS)/glass beads and vortexed. PBS with resuspended bacteria was di-luted. Droplets of 25 μL from each dilution were inoculated on BH agar plates and incubated (37°C, 24 h). Visible colonies were counted, transformed to Log 10 and statistically analyzed with one way ANOVA and Tukey HSD tests.Results: Gaseous ozone showed better killing ability then saline (p<0.05) while octenidine dihydrochloride, chlorhexidine and NaOCl solutions were found equally effective in disinfecting canal walls (p>0.05). The saline group demonstrated highest number of remain-ing microorganisms in dentinal tubules (p<0.05). Disinfection with gaseous ozone was not as effective as octenidine dihydrochloride in disinfecting deep dentine layers (p<0.05). Octenidine dihydrochloride was less effective then chlorhexidine and NaOCL solutions (p<0.05) that showed complete sterilization. Conclusion: Gaseous ozone could not be considered as effective as conventional irrigants in disinfecting root canals infected with resis-tant bacteria such as E. faecalis.

13.00/14.30 LUNCH

14.30 / 16.30

Chairperson: Lars Bjorndal

14.30 – 14.50

Organic tissue dissolution capacity of octenidine dihydro-

chloride in comparison with contemporary irrigants Burak Guneser, MB Akbulut, AU Eldeniz Department of Endodontics, Selcuk University, Konya, Turkey

Abstract

Aim: To compare the tissue-dissolution capacity of octenidine dihydro-chloride as a new antiseptic solution (Octenisept®, Schülke&Mayr, Germany) with sodium hypoclorite solutions (2.5% and 5.25% NaOCl)



(Caglayan Kimya, Turkey), 17% ethylenediamintetraacetic acid (EDTA) (Merck, Darmstadt, Germany), 2% chlorhexidine (CHX) (Imicryl, Tur-key) and 0.9% saline (I.E Uragay, Turkey) on bovine tissues in vitro.Methodology: Frozen tissue specimens obtained from palates were cut into pieces of 4x4x2 mm by using a scalpel and thawed in 30 mL of isotonic saline solution at room temperature for 30 min before use. The specimens randomly divided into 6 groups (n=64 per group) (i) Octenidine dihydrochloride, (ii) 2.5% NaOCl, (iii) 5.25% NaOCl, (iv) EDTA, (v) CHX and (vi) saline as a control group. The specimens were weighed before placing in separate glass vials containing 5 mL of each test solution with two different temperatures; room tempera-ture (RT) (n=32) or 45ºC degrees (n=32). After incubation for 15, 30, 45 and 60 min (n=8) at 37ºC, specimens were washed in saline, blotted dry and weighed again. The percentage of weight loss was calculated and statistically analysed with one-way ANOVA and tukey post hoc tests (α=0.05).Results: All the solutions except saline and octenidine dihydrochlo-ride dissolved the organic tissue. NaOCl solutions were signifi cantly more effective on tissue dissolution compared to EDTA and CHX at all time intervals (p>0.05). There was no statistically difference between EDTA and CHX solutions (p>0.05). Heating the NaOCl, EDTA and CHX solutions to 45ºC considerably enhanced their tissue dissolution ca-pability when compared with the RT. Tissue specimens incubated with saline and octenidine dihydrochloride increased in weight at both RT and 45ºC.Conclusions: Within the limitations of this in vitro study, it can be con-cluded that octenidine dihydrochloride solution did not have any or-ganic tissue dissolution capacity when compared with other irrigants currently in use in endodontics.

14.50 – 15.10

Evaluating the effect of surfactant addition to EDTA on the

microhardness of root dentineIlgin Akcay, B Hakan SenDepartment of Endodontology, School of Dentistry, Ege University, Izmir, Turkey

Abstract

Aim: To evaluate the effect of 5% EDTA solution with or without dif-ferent percent’s of surfactants on the microhardness of human root dentin, in vitro. Methodology: The crowns of 20 single-rooted human teeth were dis-carded at the cement-enamel junction and the roots were bisected longitudinally into a total of 40 segments, were embedded in auto polymerizing polyester, and were grounded fl at with silicon carbide abrasive papers. The specimens were randomly divided into the fol-lowing 5 groups, based on the test solutions used: (1) group1, % EDTA (n=10); (2) group2, 5% EDTA with 0.25% cetrimide (n=10); (3) group3, 5% EDTA with 0.5% cetrimide (n=10); (4) group4, control (0.25% cet-rimide) (n=5); and (5) group5, control (0.5% cetrimide) (n=5). The test solutions were applied for 1 minute. The reference microhardness values of untreated specimens were recorded at depth of 100 μm from the pulp-dentin interface at the mid-root level of the root dentin with a Vickers diamond microhardness tester (indenter under a 50-g load and a 10-second dwell time) in Vickers hardness number (VHN). Post-treatment microhardness values were obtained in the same manner as the initial ones. Differences between pre and postopera-tive microhardness values were recorded. Results were statistically analyzed using the non-parametric Kruskal Wallis test and Dunn’s test for post-hoc comparisons (p < .05).Results: All tested solutions decreased the microhardness of the root dentin. EDTA with 0.25% cetrimide and with 0.5% cetrimide had the greatest overall effect, causing an obvious decrease in dentin micro-hardness without a signifi cant difference (p > .05) from each other. However, both regiments differed signifi cantly from the EDTA solu-tion alone (p > .05). There was no signifi cant difference between EDTA and control groups in the reduction of microhardness.Conclusion: It could be concluded that surfactant addition to EDTA signifi cantly reduced the microhardness of root dentin.

15.10 – 15.30

Effect of different single-cone obturation techniques on

vertical root fracture resistanceHandan Ersev, B Ylmaz, R Erien, E Özcan, EPehlivanolu Department of Endodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey

Abstract

The purpose of this study was to evaluate the effect of different sin-gle-cone obturation techniques on vertical root fracture resistance. Ninety extracted single-canal mandibular premolar teeth were sec-tioned, leaving a standard root length of 12 mm. Labiolingual and mesiodistal diameters were measured and the teeth were randomly divided into 6 groups (n=15). There were no statistically signifi cant differences between groups in terms of the diameters. In Group 1, no instrumentation or obturation were performed. Rest of the roots was chemomechanically prepared with nickel-titanium rotary NiTi-TEE (Sendoline, Sweden) 0.04 taper instruments to a size 30 at the working length using crown-down technique. Group 2 was left un-obturated. Groups 3 to 6 were fi lled with the following obturation systems according to the manufacturers’ instructions: 2Seal (VDW, Germany), EndoREZ (Ultradent, USA), ActivGP (Brasseler USA, USA) and GuttaFlow (Colténe-Whaledent, Germany), respectively. Single-cone technique was used in all groups. All of the roots were mounted vertically in self-cure acrylic resin blocks exposing 8 mm of the coro-nal part and subjected to a gradually increasing force (1 mm/min) which was directed vertically, parallel to the long axis of the roots. The force when the fracture occurred was recorded as Newtons. The data were analyzed using Kruskal-Wallis and post-hoc Dunn’s multiple comparison tests. A p value below .05 was considered to be signifi cant. The following mean fracture resistance values were recorded in Groups 1 to 6: 1107±412, 862±242, 1100±352, 1020±328, 1183±352 and 805±303 N, respectively. The only signifi cant difference was detected between the roots obturated with GuttaFlow and Ac-tivGP systems (p<0.05). Under the conditions of the present study, GuttaFlow system seems not to restore the fracture resistance of in-strumented roots as ActivGP system does.

15.30 – 15.50

Push-out bond strength o Gutta-Percha/AH plus and

endorez systems following different irrigation protocols AD Kececi, Ureyen Kaya Bulem, E Sartekin, H Erdogan, HE Güldas Suleyman Demirel University, Faculty of Dentistry, Department of Endodontics, Isparta, TurkeySelçuk University, Faculty of Dentistry, Department of Endodontics, Konya, Turkey

Abstract

Aim. To evaluate the effects of three new irrigation protocols on bonding ability of two different resin-based obturation systems in comparison with conventional protocol. Methodology. One hundred eight mandibular premolars were decor-onated and root lengths were standardized to 14mm. The root canals were prepared to an apical size 35/.06 and randomly divided into four different test (n=24) and one control (n=12) groups according to the following irrigation protocols: 2.5% NaOCl+17% EDTA; 2.5% NaOCl with passive ultrasonic irrigation (PUI); 2% Chlorhexidine (CHX); 2% CHX with PUI and saline. Each group was divided into two subgroups and obturated with one of the following resin based systems: Gutta-percha/AH-Plus or EndoRez. Three serial 1.00±0.05 mm thick root slices were prepared. Bonding of fi lling materials to root canal dentin was tested with push-out at a cross-head speed of 0.5 mm/min using a universal testing machine. The data were analyzed with One-way ANOVA, Mann-Whitney and Kruskall-Wallis tests. Results. Irrigation protocols did not affect the bonding ability of test-ed resin-based obturation systems signifi cantly (χ2=2.948, p>0.05). Guttapercha/AH-Plus root fi llings had greater push-out values than EndoRez (p=0.00). There were signifi cant differences among






24

the groups (p=0.00). Bond strength of the tested groups were CHX/AH-Plus, NaOCl+PUI/AH-Plus, Saline/AH-Plus, CHX+PUI/AH-Plus, NaOCl+EDTA/AH-Plus, CHX+PUI/EndoRez, NaOCl+EDTA/EndoRez, NaOCl+PUI/EndoRez, CHX/EndoRez, saline/EndoRez in descending order. Conclusions. The difference among the groups was found to be relat-ed not with the irrigation protocols but the with obturation systems.

15.50 – 16.10

Root canal treatment of elements with periapical cysts,

MTA vs gutta-perchaAndreas Krokidis, N Barabanti, Antonio Cerutti, Vasilios Kaitsas, G Siskos University of Athens, GreeceUniversity of Brescia, ItalyUniversity of Siena, Italy

Abstract

This pilot clinical study examined the ability of two different end-odontic fi lling materials (MTA vs. gutta-percha) in healing (two years examination) of teeth with radicular cysts designated for endodontic surgery. Methods: Teeth with radicular cyst were selected (n=8) after differ-ential diagnosis (DD) to periapical periodontitis, mostly incisors after traumas. DD was performed radiografi cally and clinically. Root canal treatments (RCT) were carried out by using GT and GtX fi les, irriga-tion with NaOCL 6% and chlorhexidine. Medications with CaOH were performed until exudate in root canals was not present. When ready for obturation the fi lling material was randomly selected MTA was used . in four cases while the other teeth were obturarted using hot gutta-percha vertical condensation. All teeth have been evaluated radiographically and clinically every six months. Percussion pain, enlarged periradicular bone on buccal or lingual sides, increase of bone absorption (XRay), presence of fi stula and tooth mobility were monitored, when at least two of these variables of the check list were found poorer, the case was scheduled for endodontic surgery. Re-sults: two years after the treatment two cases treated with gutta-percha failed after six mounths and surgery was performed. Between the visits it was noticed a poor sealing in the apical region, in fact handling of gutta-percha in wide apex diameters in all four cases was found diffi cult. Conclusions: within the limitations of this study, time and sample size, the conclusions could be optimistic for treat-ing open apex teeth with large periapical lesions routinely using MTA before performing endodontic surgery.

16.10 – 16.30

Postoperative pain after the application of three different

obturation techniques Luis Oscar Alonso Ezpeleta, Francesca Monticelli, Juan Jose Segura Ejea, Jose Maria Nieto de Pablos, Jesus Mena Alvarez University of Zaragoza, University of Sevilla and University of Alfonso X el Sabio, Spain

Abstract

Aim: To determine the discomfort experienced by patients post-treatment root canal and to correlate it with obturation techniques and vital or non-vital pulp.Methodology: Two hundred four patients (105 men and 99 women), with ages ranged from 12 to 77 years, were randomly recruited. Pa-tients completed a 10-cm visual analogue scale (VAS) that ranked the level of discomfort experienced post-treatment root canal; Pain levels were assessed after 2, 6 hours, and 1, 2, 3, 4, 5, 6 and 7 days (during the fi rst week post-treatment)Results: The mean discomfort level post-treatment root canal was; 0,30 ± 0,65 (two hours later), 2,44 ± 1,56 (six hours later), 1,89 ± 1,65 (a day later), 0,93 ± 1,25 (two days later), 0,49 ± 0,90 (three days later), 0,22 ± 0,54 (four days later), 0,08 ± 0,29 (fi ve days later), 0,04 ± 0,21 (six days later), and 0,03 ± 0,17 (seven days later) in a VAS between 0

and 10. Only 17,1% percent of patients did not experience discomfort. Discomfort during root canal treatment was signifi cantly greater ac-cording to the type of obturation (p < 0.05).Conclusions: The results of the present paper, together with previous fi ndings, showed signifi cant infl uence of the type of obturation tech-niques on patients’ discomfort post-treatment root canal.


17.00 / 18.40

Chairperson: Unni Endal

17.00 – 17.20

A new carrier-based obturation techniqueValentina Vincenzi, Luca TestarelliSapienza University of Rome - School of Dentistry, Italy

Abstract

The lecture will present a new carrier-based obturation technique (Real Seal 1 T, SybronEndo, Orange,CA) which utilizes the innova-tive ResilonT root canal fi lling material instead of traditional gutta-percha. ResilonT material has a chemical link with the sealer and with the bonding layer on the dentine surface of the root canal wall. This should lead to a monoblock obturation that improve the seal-ing ability of the technique. Moreover in a carrier-based technique the ResilonT coating binds more effi ciently with the carrier, avoiding separation of the two materials during intracanal use. The advantag-es of the new technique versus traditional carrier-based technique will be explained using SEM analysis, confocal microscopy studies, and other researches showing differences in shrinkage upon cooling, dissolution of the carrier with or without solvents, fl ow and adhesion of the Resilon-based material compared to traditional gutta-percha. Moreover, researches made by the University of Rome evaluating the behavior of different fi lling carrier techniques in curved canals and the sealing ability in vitro will be presented and discussed. At the end, clinical cases fi lled with new material will be shown, analyzing the pro’s and co’s of new and old carrier-based techniques in end-odontics.

17.20 – 17.40

Cleaning ability of the SAF system with MTAD or Citric-

acid Özgur Genc, S. Kaya, Ö. Er Yuzuncuyıl University, Faculty of Dentistry, Van, Turkey. Dicle University,Faculty of Dentistry, Diyarbakır, Turkey. Erciyes University, Faculty of Dentistry, Kayseri, Turkey

Abstract

The aim of this study was to evaluate the cleaning ability of the Self-Adjusting fi le system irrigation with MTAD and Citric –acid. Twenty-three single-rooted human teeth was used for the study.Coronal parts of the teeth were cut with a high-speed diamond bur. The working length was determined and canals were instrumented manually up to a size of 20 K fi le. A SAF fi le was used for preparation of the root ca-nals using in-and-out vibrating handpiece as described by Metzger et al. Irrigation was performed continuously during the instrumentation using a special irrigation apparatus (VATEA Irrigation Device). In each group different irrigation solutions were used with this irrigation sys-tem as following:Group 1: MTAD + 5.25 % NaOCl, Group 2: 20 % Citric acid + 5.25 % NaOCl, Group 3: Control (5.25 % NaOCl). Distilled water was used for the fi nal fl ush. All roots were split longitudinally and subjected to Scanning electron microscopy. The presence of debris and the smear layer in the coronal, middle and apical thirds of the ca-nal were evaluated using fi ve–score evaluation systems through the analysis of SEM images. Citric-acid was more effective than MTAD on the elimination of smear layer in the three thirds of the canal. The



operation of the SAF system with continuous irrigation coupled with alternating sodium hypoclorite and citric-acid treatment resulted in a clean and nearly smear-free dentinal walls.

17.40 – 18.00

Effect of intracanal medication on the apical seal with

MTA using radioisotope methodsManuel Marques Ferreira, Margarida Abrantes, Lusitana Moura Pega, Tânia Afonso, Eunice Carrilho, Filomena BotelhoDentistry, University of Coimbra, PortugalInstitute of Biophysics and Biomathmatics-IBILI, University of Coimbra, Portugal

Abstract

Aim - This study aims to evaluate the effect of calcium hydroxide, used as intracanal medication, on the apical microleakage of mineral trioxide aggregate (MTA) placed as an apical barrier in permanent teeth with simulated immature apices.Methodology - thirty-four single-rooted extracted teeth were selected according to predetermined criteria and kept in saline solution. After the crowns were sectioned to obtain 17 mm- long root segments, the 2 apical mm of each root were resected and an open apex model was created. The root canal of each tooth was prepared by the same op-erator using rotary ProFile® instruments. The root segments were randomly assigned to 4 groups: G1(n=12)-medication with Ca(OH)2 for 1 week, G2 (n=12)- without medication, G3(n=5) - positive control group and G4 (n=5) - negative control group. In all groups a 4mm api-cal barrier of MTA was placed with the exception of group G3 (positive control group).Two coats of nail polish were applied to the external surface of each root except for the resected apical root end, unlike the negative con-trol group, where the root ends were also sealed with nail polish. On the 7th and the 28th day the apices of the teeth were submersed in a solution of 99mTc-Pertechnetate during 3 hours. The radioactivity was counted using a gamma counter and a gamma camera.Results - The results revealed statistically signifi cant differences between the 2 control groups and the 2 experimental groups with respect to the microleakage. Within the experimental groups there were not found any statistically signifi cant differences. Conclusions: The results obtained with 99mTc-Pertechnetate tech-nique suggest that medication with Ca(OH)2 had no signifi cant effect on MTA leakage.

18.00 – 18.20

A comparison of fl ow capacity and fi ltration among

different obturation materials in artifi cial lateral canals Laura Sesé Garcia, M Real, A González-Gutiérrez, L Gancedo, J Bascones, E García-BarberoDepartament of Endodontics and Restorative Dentistry, Complutense University Dental School, Madrid, Spain

Abstract

AIM: The purpose of this study was to evaluate the movement of Resi-lon® (SybronEndo®, USA) and different commercial points of gutta-percha into artifi cial lateral canals when subjected to warm vertical compaction, and to determine whether this ability can infl uence in the capacity of sealing. METHODOLOGY: Evaluation of the penetration of the material at each lateral canalWe selected resin blocks with a standardized main root canal and lateral canals (Thermafi l Training Blocks, Dentsply/Maillefer, Swit-zeland). Using the continuous wave technique (System B), fi fteen obturations were performed for each experimental group. Resilon® cones, as well as different brands of gutta-percha: Maillefer® (Den-stply, Switzeland), Roeko® (Colténe/Whaledent, Germany) and K3 (SybronEndo®, USA) were thermoplastifi ed. Methylene Blue was inyected in the most coronal lateral canal using an inyector (UltraMi-croPump III) with a microprocessor controller (Micro4) (World Preci-

sion Instruments, USA). The specimens were radiographed, photo-graphed and cross-sectioned. Image analysis was used to quantify the extent of the obturation material in the lateral canal, as well as dye penetration. An Anova and the post hoc Duncan´s multiple range test were used to analyse the penetration of the material at each lat-eral canal. Differences between dye penetration were investigated using a Kruskall-Wallis test. Spearman correlation was performed to determine if the capacity of fl ow have a direct relationship with fi ltration.RESULTS: Statistically signifi cant differences were found in the com-parative analysis of the fl ow capacity, with Resilon® group recording the highest penetration (1,8 mm). Roeko® exhibited the lowest fi ltra-tion (1,26 mm2 of area without presence of dye), with a signifi cant dif-ference (p<0.05) respect Resilon® (0,43 mm2) and Maillefer® (0,37 mm2).

18.20 – 18.40

Glucose penetration of new, epoxi-, methacrylate-resin

and silicon based root canal sealers B Ureyen Kaya, Betul Gunes, M Akman, AD Keçeci, S Belli Suleyman Demirel University, Faculty of Dentistry, Department of Endodontics, Isparta/TurkeySelcuk University, Faculty of Dentistry, Department of Endodontics, Konya/Turkey

Abstract

Aim: To compare the sealing ability of a new oil-resin sealer (Tech BIOSEALERTM ENDO) with AH plus, RoekoSeal and RealSealTM.Methods: Seventy extracted human single-rooted teeth were decoro-nated and the root canals were prepared using ProTaper rotary fi les up to F3 as MAF. Irrigation was performed with 2.5% sodium hypo-chlorite solution after each instrument. Smear layer was removed 3 ml 2.5% NaOCl, 17% EDTA and 3 mL distilled water was performed to remove the smear layer. The roots were randomly divided into four different test (n=15) and two control (n=5) groups according to the sealer materials: AH Plus (Dentsply DeTrey, Konstanz, Germany); RoekoSeal (Coltène/Whaledent Germany); RealSealTM (SybronEndo, Orange CA); Tech BIOSEALERTM ENDO (ISASAN S.R.L Via Bellini, Italia).The root canals were obturated with one of the tested sealers and ProTaper F3 gutta-percha points using singlecone technique. The specimens were stored at 37°C and 100% humidity for 7 days. The leaked glucose concentration was measured spectrophotometrically at 500 nm wavelength at 1th, 7th and 28 days. Data were converted to mmol/L and statistically analyzed with Repeated Measures ANOVA and Paired Samples T tests (p<0.05).Results: RealSeal (1.95±1.42) indicated signifi cantly more glucose penetration than AH Plus (0.95±0.59), RoekoSeal (1.26±0.59) and Tech BiosealerTM Endo (1.11±0.47) at the fi rst day (p<0.05). The leaked glucose concentrations of the tested sealers were RealSeal, AH Plus, RoekoSeal and Tech BIOSEALERTM ENDO in descending order.However, there were no statistical differences among the tested seal-er at the 7th and 28th days (p>0.05).Conclusions: None of the tested materials showed a hermetic seal-ing in root canals. The recent sealer Tech BIOSEALERTM ENDO showed similar patterns of glucose penetration with the other resin and silicone based root canal sealers.Key Words: AH Plus, glucose penetration, RealSeal, RoekoSeal, Tech BiosealerTM Endo.






26

ROOM ELLISSESATURDAY, 17TH SEPTEMBER 2011

8.30 / 16.10

8.30/10.30

Chairperson: Arnaldo Castellucci

8.30 – 8.50

Root canal preparation with three different nickel-

titanium rotary fi les evaluated with cross-sectional and

x-rays images analysisYolanda Custodio-Menendez, D Rubio-Flores, E García Barbero Department of Conservative Dentistry. Endodontic Service. Complutense University of Madrid, Spain

Abstract

AIM: Assessing shaping ability and deformation degree on curved root canals with rotary instrumentation.MATERIALS AND METHODS: Three different rotary systems were evaluated (ProTaper Universal®, Mtwo® and Twisted Files®). 62 curved root canals were randomizely divided into three groups after glide path with K15 stainless steel fi le. Tooth were immersed in poly-ester resin (Chronolite 2195) blocks. Blocks were sectioned using a microtome obtaining three slices (apical, middle and coronal). X- rays and cross- sectional photographs from apical and middle thirds of the blocks were taken pre- and post- rotary instrumentation. Two pa-rameters were assessed for x- rays: changes in curvature degree and distance from the tip of the fi le to a radiopaque device with x- rays images analyzer (Meazure® and Image Tool 3.0®). Four parameters were measured for cross- sectional images analysis with Image Tool 3.0®: amount of dentine removed (changes in area in mm2), variation of canal shape factor, and amount and direction of transportation X (amount of enlargement from the outer portion) and of transporta-tion Y (amount of enlargement from the inner portion).RESULTS: For x- rays analysis, mean values suggest that Twisted Files® samples showed less change in curvature degree (5,795º) than ProTaper Universal® (8,082º) and Mtwo® (11,509º). Besides, the change in distance to the radiopaque device is also lower for Twisted Files® (1,485 mm)than ProTaper Universal® (1,825 mm) and Mtwo® (1,724mm). For cross- sectional images, mean values sug-gest that Twisted Files® samples removed less dentin (0,124 mm) than ProTaper Universal® (0,359 mm) and Mtwo® (0,352 mm); and produced less transportation X and Y. ProTaper Universal® rounded the canals more than Mtwo® and Twisted Files®. CONCLUSION: Twisted Files® system shows less dentin removal with less transportation and changes in curvature degree and distance to the radiopaque device than Mtwo® and ProTaper Universal®.

8.50 – 9.10

IG-File: a new instrument for the evaluation of apical

gaugingMaria Patrizia Di Caprio, Alfredo Iandolo, Michele Simeone School of Dentistry, University of Naples, Federico II

Abstract

IG-File (Iandolo Gauging File) is a new instrument designed by one of the Authors (AI). At today the apical gauging is performed using the common K-File in Ni-Ti alloy. This kind of fi le have been manufac-tured in order to shape the root canals. Consequently they have some disadvantages regarding the measurement of the apical foramen (apical gauging). In this Oral Presentation the IG-File is presented, it is the fi rst instrument designed exclusively for this issue. In vivo clini-cal use og the IG-fi le and results of trials in vitro and are presented in order to explain the advantages in the use of this instrument and its real effi ciency.

9.10 – 9.30

Pro arguments for the importance of endodontic

treatment in third molars

Cristina Toma, Andrei Cristina GabrielaResident at the Endodontic Department of University of Dental

Medicine “Iuliu Hatieganu” Cluj-Napoca, Romania

Abstract

With all the scientifi c evolution in Endodontics many practitioners still choose to extract the third molars instead of treating them. This attitude is somehow justifi ed by the multitude of anatomic variations and the diffi culty of endodontic treatment. We can see the true im-portance of third molars in terminal edentation where they are the last posterior teeth. Through this study we sustain and encourage the treatment of third molars, regardless the diffi culty of the intervation because of the endodontic space complexity and restricted access in the posterior area.This study was taken on 40, third molars, in vitro. All the teeth were prepared through stepdown technique and a lot of attention was given to the negociation of the foramen. Root canals were shaped with ProTaper System until an average of 8% taper. The endodontic space was cleaned with copious irrigations with NaOCl 5,25%, EDTA 17%, H2O2 3%, CITRIC ACID 40%. To improve the effect of irrigations all were ultrasonic activated for 10-15 sec. A lot of importance was given to irrigations in order to clean every detail in the endodontic space that couldn’t be reached through mechanical treatment (col-lateral, secondary canals, isthmus).For endodontic obturation we used the warm vertical compactation with E&Q Master System from Meta Co.Two methods were used to evaluate the results:1) Classic x-ray for all teeth on 3x4cm fi lm from mesio-distal and buccal-lingual side 2) Impregnation with methilen blue of the roots, transversal section at 3 mm from apex with microtome in 0,2 mm slices. All the slices were analysed in electronic microscopy and the accuracy of root ca-nal sealing appreciated.Through a rigorous endodontic treatment the third molars can be saved and the patients rescued from removable prosthetics.

9.30 – 9.50

New trends in the restoration of endodontic treated teeth

Giancarlo PongioneESE Certifi cate Member, Active member SIE

Abstract

The goal of an endodontic treatment is to remove the pulp and the bacteria from the canals and to avoid reinfection of them with the root canal fi lling . According to the literature the “Coronal Leakage” is one of the main reasons for endodontic failure. Therefore after the end-odontic treatment we have to restore the teeth as soon as possible to seal the main entry point of the bacteria and to avoid the fracture of the residual cusps. Use of the adhesive technique for the restoration of anterior and posterior endodontic treated teeth allows the aes-thetic and functional restoration with minimum loss of healthy dental tissue. A difference in the treatment of the anterior and the posterior teeth will be shown suggesting when and how to use a fi ber post. During the presentation when to use a direct composit restoration or when to use an indirect composite and ceramic restoration ( inlays, onlays overlays, veneers, crowns ) will be demonstrated.



9.50 – 10.10

Vertical root fracture resistance of teeth after ultrasonic

and masseran retrieval of fractured instrumentsMuzeyyen Gerek, ED Baser, MB Kayahan, H Sunay, RF Kaptan, G Bayirli Yeditepe University Faculty of Dentistry, Istanbul, Turkey

Abstract

The aim of this study was to evaluate the vertical fracture resistance of roots after retrieval of fractured instruments using ultrasonic tips and Masseran technique. Thirty nine extracted human anterior teeth with single and straight roots were used. The anatomical crown of the teeth were removed until the full length of the teeth were 13 mm. All samples were instrumented with the step-back technique to a size #25 K fi le. The teeth were randomly divided into three groups. Thirteen teeth were remained as control group. The 30#K fi les were notched to a depth of half of the instrument with a # 2 round bur, 3 mm from the tip to facilate fi le separation at this point. The teeth in the experimental groups were radiographed to ensure that the separation occurred in the middle third of the canal. All instrument removal procedures were performed by the same operator. The sam-ples were subjected to fracture strength test using a universal testing machine. For each root the force at the time of fracture was recorded in Newtons. The results were statistically analyzed. According to the results of this study control group showed the highest fracture re-sistance followed by ultrasonic group. The roots in which the broken instruments were retrieved by Masseran technique showed better fracture resistance than the other experimental group. Conclusion: The results of this study showed that retrieving the broken instru-ments with Masseran technique increased the in vitro resistance to fracture of single canal teeth when compared to ultrasonic tips.


11.00/13.00

Chairperson: Massimo Giovarruscio

11.00 – 11.20

A new sequence for shaping root canals: a more

conservative and safer approachGiuseppe SqueoUniversity of Foggia, Italy

Abstract

The shaping of the root canal constitutes - along with the cleaning and the fi lling of the root canal - a fundamental phase of the end-odontic treatment which, if carried out correctly, leads to a success-ful outcome. It is, however, also the most critical phase, because after all, more or less rigid metal instruments have to be inserted into the anatomy of the canal which can be rather complex at times, with all the risks that this entails. Although the introduction of NiTi instruments has speeded up this phase, making it more predictable and more gentle on the anatomy of the canal, the dentist is also faced with an increased risk of instrument fracture inside the root canal. Recently, the company Komet has developed a new range of me-chanical NiTi instruments which, thanks to its special properties, reduces the stress accumulated by each individual instrument to a minimum, thus proportionally reducing the risk of instrument frac-ture. The purpose of this presentation is to emphasise the proper-ties of this sequence, highlighting its advantages with regard to both clinical experience and scientifi c evidence.

11.20 – 11.40

Debridement quality of single F2 fi le and Self-Adjusted

File in oval-shaped canals Erick M Souza, G De-Deus, B Barino, RQ Zamolyi, J Maia, C Reis, A Kfi r, Jr. A Fonseca, S Fidel, RAS Fidel Veiga de Almeida University (UVA), Rio de Janeiro, RJ, BrazilUniversity Center of Maranho UNICEUMA, So Luis, MA, BrazilBonsucesso Federal Hospital (HFB), Rio de Janeiro, RJ, BrazilRio de Janeiro State University (UERJ), Rio de Janeiro, RJ, BrazilThe Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

Abstract

Results from high-defi nition micro-CT studies have underlined the inadequate quality of mechanical preparation by the current NiTi ro-tary systems. The amount of mechanically prepared root canal sur-face is frequently below 60%, resulting in a substantial amount of untreated dentin areas. This defi cient mechanical preparation could offer an opportunity for remaining microorganisms to recolonize the fi lled canal space, resulting in endodontic failure.Recently a preparation technique using only the F2 ProTaper instru-ment in a reciprocating movement was published. The concept of us-ing a single NiTi instrument to prepare the entire root canal is inter-esting, because the learning curve is considerably reduced. It is also more cost-effective than the conventional multi-fi le rotary systems.More recently an innovative instrument, Self Adjusting File (SAF), was released. It consists of a hollow fi le composed of lattice threads that are lightly abrasive and allow for dentin removal with a back-and-forth grinding motion. Initial reports of SAF system sound promising. SAF is designed as a compressible fi le with the ability to adapt itself to the root canal cross-section. It is claimed to adapt itself to either round, oval or even long-oval cross sections of root canals. In this oral presentation we will discuss the results on two new re-cently published articles, laying emphasis on the debridment limita-tions of current mechanical instrumentation techniques, including the Single F2 fi le technique, especially in oval-shaped canals. On the other hand, the so-called cleaning-shaping-irrigation system, SAF, has signifi cantly improved tissue debridment in oval canals. Probably the interplay of SAF ability to adapt itself to the cross section of the canal and the continuous irrigation explain the superior debridment quality of SAF system. As oval-shaped canals represent a real chal-lenge to clean, SAF represents a promising alternative for improve-ment in root canal debridment.

11.40 – 12.00

Root canal morphology of maxillary molar teeth and its

impact on gauging and shapingMonika Marending Soltermann, M Zehnder, F Paqué Center of Dental Medicine, Clinic of Preventive Dentistry, Periodontology and Cariology, University of Zurich, Zurich, Switzerland

AbstractEffective root canal debridement requires adequate apical enlarge-ment without weakening the root by excessive dentine removal. In this context, assessment of canal size and shape prior to instrumen-tation would be important information. However, with current tools, the complexity of root canal morphology prevents the clinician from making more than an educated guess on apical canal anatomy.A series of studies related to the topic was performed using maxil-lary molar teeth. These have generally four root canals, with different cross-sectional shapes and variable diameters. Moreover, canal mor-phology is not only different between one type of canal to the other, but also changing between different root levels. Using micro-computed tomography, canal confi gurations, forms and dimensions were visual-ized and calculated in the ex vivo situation in a highly accurate manner. The non-invasiveness of the method allowed to follow each specimen through different treatment steps: apical gauging, instrumentation to the master apical rotary, and subsequent apical enlargement.This presentation shows two- and three-dimensionally the initial anatomy of maxillary molar teeth with four independent root canals.






28

The ability of sizing the apical anatomy after a crown down procedure by K-fi les in comparison to the oval-shaped Lightspeed LSX instru-ments and the alteration in canal shape during different preparation steps using manual or rotary instrumentation are illustrated. The re-sults are discussed in relation to the literature.

12.00 – 12.20

A new device for removing fractured instrumentsMartin DominiqueUniversity Paris VII Denis Diderot Paris, France

Abstract

The risk of endodontic instrument separation has increased in recent years with the use of rotary instrumentation for root canal shaping. The EndoRescue® kit (Komet, Germany) has recently been launched. It features a specifi c pointer which is intended to prepare the work of a trephine drill. A characteristic is the miniaturization of the tre-phine drill: three sizes are currently available matching the size of Gates Glidden drills No. 2, 3 and 4. First, a straight line access to the fragment is established by removing the minimum quantity of dentin. Secondly, the coronal part of the fragment is disengaged and cen-tered by the pointer. Thirdly, the trephine drill is used in a counter-clockwise motion (300 rpm) to unscrew the fragment and remove it. The limitation of the EndoRescue® kit is a fragment located around or beyond a canal curvature. In this case, the blades of the trephine drill free the coronal part of the fragment. The drill then comes up against it and stops on the fragment. In this situation, it is possible to combine the action of the trephine drill and the use of a needle fi lled with self-curing or dual composite resin. After composite curing, the needle is removed in a counterclockwise rotation: the fragment en-trapped inside the composite comes out with the needle. Currently, nickel-titanium instruments are involved in the vast majority of in-strument fracture. The EndoRescue® kit is specifi cally intended for these kind of cases. Compared to other available instruments, it al-lows a minimum amount of dentin removal as well as reduces the time required for this procedure.

12.20 – 12.40

The endodontic management of teeth with open apices Philip MitchellDental Institute, Kings College London, Guys Tower, London SE1 9RT

Abstract

The presentation will cover the endodontic and general restorative management of teeth with immature apices and infl ammatory root resorption. Protocols for disinfection and obturation of such teeth in-cluding the use of biodynamic materials such as MTA and Biodentine will be discussed. In addition, there will be an overview of more tradi-tional approaches. Finally, the prognosis and possibility of strength-ening such teeth will be covered.

12.40 – 13.00

The reciprocating motion: a new era in endodontic

instrumentation?Nehme WalidPast president lebanese Society of EndodontologySaint Joseph University of Beirut, Lebanon

Abstract

Nickel- titanium instruments had a major impact on root canal prep-aration in the lat decade. They offer many advantages over conven-tional fi les, such as fl exibility, cutting effi ciency and reduction of the time required for shaping canals. Nevertheless clinician still has to face two major concerns: instruments fracture and cross contamina-tion due to repeated use. A single NiTi rotary instrument technique with a reciprocating movement has been proposed to overcome these concerns. The aim of this presentation is to highlight on the different reciprocating systems. To investigate on some aspects of the recip-rocating movement using NI-Ti rotary fi les, namely the shaping abil-

ity, the cutting ability, the working time and the resistance to break-age. To compare between continuous and reciprocating movement of NiTi fi les from same brand and from different brands as well. Then through Clinical cases, to show clinician the advantages and limita-tion of each of the movements.

13.00/14.30 LUNCH

14.30 / 16.10

Chairperson: Cristiano Fabiani

14.30 – 14.50

Shaping for cleansing: apical preparation size and

preparation taperFlavio PalazziUniversity of Naples, Italy

AbstractSuccess of root canal treatment is dependent upon the effective re-moval of bacterial biofi lms and their byproducts from the root canal system (RCS). Irrigation with antibacterial solutions is considered complementary to instrumentation in the removal of bacteria, debris and necrotic tissue, especially from areas of the RCS that remain un-prepared by mechanical instruments. Apart from the rational selec-tion of irrigants, it has been shown that the volume of irrigants is directly related to effectiveness of disinfection and root canal cleanli-ness. Different techniques and irrigant delivery devices are available for improving the fl ow and distribution of irrigating solutions within the RCS, because traditional needle irrigation is relatively ineffec-tive in fl ushing hard and soft tissue remnants from the apical third: needles deliver solutions no further than 1 mm beyond the their tip. Additionally, gas entrapment prevents optimal irrigants delivery and fl ow. Sonic or ultrasonic activated fi les ability to displace gas pocket as their antimicrobial debridement effectiveness in the apical areas, are questionable too: apical preparation size and taper and effective vibration displacement amplitudes seem determining. Recently, api-cal negative pressure irrigation have been shown to deliver irrigants in the apical portions of the RCS in a safe and effective manner. This is directly related to the mechanical instrumentation, the larger is the preparation sizes and taper the more effective is the irrigation. No consensus exists regarding the minimum apical preparation size or taper, considering that complex root canal anatomy can affect the effectiveness of debridement and smear layer removal, render-ing them unpredictable in the apical region. Moreover increasing the apical preparation size might be diffi cult or even unfeasible in thin and curved roots and lead to transportation of the canal system and possible iatrogenic damages. The ultimate goal of RCT should be to preserve as much tooth structure as possible without compromising disinfection and eradication of bacteria from the RCS.

14.50 – 15.10

Dentinal defects after root canal preparation with SAF

and ProTaperEllemieke Hin, Hagay ShemeshDepartment of Endodontology, Academic Centre of Dentistry Amsterdam, the Netherlands

AbstractAim To evaluate ex-vivo the incidence of defects in root dentine after root canal preparation with the self adjusting fi le (SAF) and ProTaper NiTi fi les. Methodology 44 extracted mandibular premolars were selected and kept in distilled water. Radiographs were taken and the diameter of the canal at 10 mm from the apex was measured. 3 groups were formed with a uniform average canal diameter of 0.7 mm. Group 1 (n=20) was left unprepared and served as negative control. Group 2 (n=12) was prepared with SAF for 4 minutes .Group 3 (n=12) was prepared with ProTaper NiTi fi les till F4. Roots were then sectioned horizontally 3, 6,



and 9 mm from the apex and observed under a microscope. The pres-ence of dentinal defects (fractures, craze lines or incomplete cracks) and their location was noted by two observers and the remaining den-tine thickness was measured for all slices. The differences between the groups were analyzed with the Fisher’s exact test and the inter-rater agreement was determined. Results No defects were observed in the roots with unprepared canals and those prepared with SAF. 4 teeth prepared with ProTaper (33%) showed defects (p<0.05) but none were completely fractured. The remaining dentine thickness and level of the root did not signifi cantly infl uence the appearance of defects. The agreement between the two observers was signifi cant (Cohen’s kappa coeffi cient>0.7). Conclusion Root canal preparation with SAF does not create defects on the root canal walls while canal prepara-tion with ProTaper may create defects such as fractures, craze lines and incomplete cracks in dentine of extracted teeth.

15.10 – 15.30

The effects of working length and canal preparation on

development of dentine defectsMiranda Stavileci, V Hoxha, A Dragidella, A Kuçi University Dentistry Clinical Center of Kosova, Department of dental pathology and endodontics, Prishtina, Kosova

AbstractAim: The aim of this study is to evaluate the effects of working length and root canal preparation on root dentine damages.Methodology: For this study fi fty mandibular extracted premolars were used. The teeth were divided in fi ve groups of ten teeth each. Specimens of the fi rst group were prepared with step-back technique with manual stainless steel K -fl exofi les (Dentsply, Maillefer, Swit-zerland) with working length set at the apical foramen; specimens of the second group were prepared same as fi rst group, except that the working length was 1 mm short; ten teeth of third group were pre-pared with crown-down technique with rotary fi le system ProTaper (Dentsply, Maillefer, Switzerland) with working length set at the api-cal foramen and specimens of fourth group were prepared same as third group, except that the working length was 1 mm short. Teeth of fi fth group were left unprepared. Root were than sectioned horizon-tally 1mm, 2 mm, 6 mm and 9 mm from the apex and observed under stereomicroscope (Brunel MX-6T Stereomicroscope, UK).The presence of dentinal defects such as fractures, craze lines and cracks were noted for all tested groups. The Fischer exact test was used to analyses the differences between groups.Results: The teeth that were prepared with working length set at api-cal foramen showed more defects than those prepared 1mm short of apical foramen (p<0.05). Root canal preparation method with ro-tary fi les system ProTaper signifi cantly affected dentine defects, than those prepared with hand fi les (p < 0.05). Conclusion: Working 1 mm short of the apical foramen might pro-duce fewer defects in the apical region and root canal preparation technique also might induce dentinal defects.

15.30 – 15.50

A novel nickel-titanium reciprocating instrumentation

technique: experimental and clinical evaluationAlessio Giansiracusa Rubini, Nicola Maria Grande, Gianluca Plotino Sapienza University of Rome - School of Dentistry

AbstractThe aim of the present lecture is to evaluate new nickel-titanium instruments (ReciprocT, VDW, Munchen Germany) which have been recently developed as a one-fi le, single-use instrumentation tech-nique. The ReciprocT instrument design and the specifi c reciprocat-ing movement provided by an innovative endodontic motor will be analyzed, illustrating advantages and disadvantages of the proposed technique. The instruments are manufactured with the M-wireT al-loy, which is supposed to provide improved mechanical resistance and fl exibility when compared to traditional NiTi alloys. ReciprocT are available in three different sizes (tip size #25, #40 and #50) and they have a variable taper. The cross section of the instruments with two cutting blades and an “S”shape design is meant to give the in-

strument an higher effi ciency for negotiation of root canals and an improved cutting ability. Both properties are useful to allow easier and faster shaping procedures, and consequently the use of a single instrument for the preparation of the entire root canal. In vitro ex-perimental data about mechanical properties of the instruments and the differences between continuous rotation and reciprocating mo-tion will be presented and discussed. The cutting ability, shown by the progression of the fi le inside the canal, and the maintenance of original anatomy will be analyzed with the aid of transparent teeth teaching models. Moreover the time of instrumentation and the risk of iatrogenic errors such as instrument separation will be analyzed and evaluated. Clinical cases performed using the above described technique will be shown, with the authors’ feedback about simplicity of use, learning curve and quality of shaping results.

15.50 – 16.10

Access preparation: Operative Microscope and Ultrasonic

Tips, indispensable technologies in order to have an

excellent endodontic treatmentMariano Malvano, Alfredo Iandolo, Claudio FarnararoPrivate practice in Naples, ItalyPrivate practice in Avellino, Italy

AbstractThe access preparation is a very important phase of the endodon-tic treatment because it makes sure to have a correct preparation and fi lling of the root canals. Any kind of mistakes occurring in this phase can spoil the fi nal success of the endodontic treatment. Cur-rent knowledge, as far as the root anatomy is concerned, and techni-cal devices we can use, such as operative microscope and ultrasonic tips, let the dentistry deal with this clinical step safely and taking eas-ily the path to the endodontic root cleaning, shaping and apical seal-ing.In the following report you will be able to see case reports and videos of access preparations effectuated in the proper way with the use of the operative microscope and ultrasonic tips. You will also be able to know the materials which have been used and the riparative technics used in case of mistakes.






30

ROOM LEONARDOTHURSDAY, 15TH SEPTEMBER 2011

14.30 / 19.00

VLADIMIR ADLIVANKINE PRIZE 10.45 /12.45


Chairperson: Caterina Ricci

14.30 – 14.50

Dentin strain produced by root-end cavity preparation

using Er: YAG laserWatanabe Satoshi, C. Kokuzawa, B. Gombo, H. Saegusa, T. Anjo, A. Ebihara, C. Kobayashi, H. SudaPulp Biology and Endodontics, Department of Restorative Sciences, Tokyo Medical and Dental University, Tokyo, Japan

Abstract

Aim: to investigate the kinetics of dentin strain and micro-fractures produced by root-end cavity preparation using Er:YAG laser and ul-trasonics.Methodology: forty roots of extracted human anterior teeth were used. After the tooth crown was removed with a diamond disc and the length of the root was adjusted to 9 mm, the root-end 3 mm was resected. Then, the root canal was instrumented to apical size 25 or 80 using the step-back technique with Gates-Glidden drills and K-fi les. The root canal was laterally condensed with gutta-percha and root canal sealer(Sealapex, Sybron Endo, USA). Strain of dentin was measured by strain gauges (Kyowa Electronic Instrument, Ja-pan) mounted on the apical third root surface during root-end cav-ity preparation using an ultrasonic device (Piezon Master 400, EMS, Switzerland, highest power setting), or Er:YAG laser (Erwin AdvErL, Morita, Japan, 140 mJ 10 pps) with water cooling. After the root-end cavity preparation, presence or absence of root fracture and the root surface morphology were observed under a microscope using Indian ink to help visualization. Results: when the root cal was prepared to apical size 25, the mean maximum strain produced by Er:YAG laser preparation of retro-cavities was signifi cantly lower than that by ultrasonic preparation (p<0.05). Preparation of root end cavities using a ultrasonic device showed a signifi cantly higher strain for root canals prepared to apical size 25, compared to those prepared to apical size 80 (p<0.05), while that using Er:YAG laser showed no signifi cant difference between the two apical sizes (p>0.05). In the microscopic observation, micro-frac-tures were found only in the ultrasonic groups. Conclusions: when the fi nal apical size of the prepared root canal is narrow, a lower dentin strain may be produced by Er:YAG laser preparation of retro-cavities compared to that by ultrasonics.

14.50 – 15.10

New approach to retrograde root canal treatment: tubes

guiding Ni-Ti instruments in retroshapingKayahan Mehmet Baybora, Ahmet Arslan, Noyan Baal, Meriç Karapnar, Esra Pamukçu GüvenYeditepe University, Faculty of Dentistry, Istanbul, Turkey

Abstract

It has been reported in some studies that there is a signifi cant per-centage of endodontically treated teeth associated with periapical pathosis and poor treatment quality. However, in some cases, such as alteration of the root canal morphology or teeth restored with posts, particularly zirconia, it can be impossible to solve the problems

non-surgically. Sometimes, root-end cavity preparation and retrofi ll-ing procedure is not enough to fi ll the entire root canal.Therefore to shape the root canal retrogradely from apical to the coronal may be recommended.The aim of this oral presentation is to present a novel retrograde root canal shaping technique in which the combination of Ni-Ti fi les and specially designed tubes were used. The idea “tubes for retrograde root canal shaping” is the improvement of conven-tional retroshaping approaches performed with hand fi les.The tube is cylindrical in shape and curved to form α angle.The long edge, on the upper side of the said angle, is 5 mm and the short edge which is on the lower part after curvature is 2 mm long. During application the long edge is held by any holder such as a haemostat. Similar to ul-trasonic surgical retrotips, the length of the edges and angle of tubes may vary according to the location of resected root. In this presenta-tion retroshaping procedure with guidance of tubes will be explained and cases will be presented performed with this technique.

15.10 – 15.30

Endodontic-periodontal lesions: new approaches Francesc Abella Sans, JA González Sánchez, R Bueno Martínez, M Roig CayónUniversitat Internacional de Catalunya, Barcelona (St. Cugat), Spain

Abstract

The interrelationships between pulpal and periodontal disease pri-marily occur by the way of the intimate anatomic and vascular con-nections between the pulp and the periodontium. Endodontic-peri-odontal lesions can be classifi ed into primary endodontic lesions, primary endodontic lesions with secondary periodontic involvement, primary periodontic lesions, primary periodontic lesions with sec-ondary endodontic involvement, or true combined lesions.In recent years, periodontal disease has been shown to be related to pulpal disease, and pulpal disease may cause periodontal lesions that behave differently from chronic destructive periodontitis. The present communication discusses the intercommunications be-tween pulpar and periodontal tissues, the effects of pulpal disease on the periodontium, periodontal disease and its effects on the pulp, differential diagnosis, and management and prognosis of endodontic and periodontal problems. It provides an overview of relevant litera-ture on root amputations and hemisections, osseous grafting proce-dures, guided tissue regeneration, vertical root fractures and surgi-cal lengthening of the clinical tooth crown.It also describes some clinical cases where the use of cone-beam computed tomography (CBCT) has been central to its diagnosis and resolution. The recent introduction of CBCT scans provide three-di-mensional information, a number of useful applications in endodon-tics, and a better differential diagnosis between pulpal and periodon-tal disease.

15.30 – 15.50

Surgical treatment of lateral lesions using chairside-

customized ultrasonic tipsAmir WeissmanDepartment of endodontology, Tel Aviv University, Israel

Abstract

Periapical lesions next to the main apical foramen, usually allow for a straightforward diagnosis and treatment. On the other hand, those which appear on the lateral aspect of the root often present a diag-nostic and treatment challenge.The differential diagnosis of lateral lesions will be discussed, focus-ing on lateral lesions of endodontic origin. Cases of lateral lesions will be presented and discussed, including horizontal and vertical root fractures, perforations and lateral canals. Identifi cation and treatment of lateral canals is especially diffi cult when root canal treatment is done through conventional access. The endodontic mi-cro-surgical approach may serve as an alternative treatment modal-ity in such cases.



A modifi cation in retro-preparation will be presented in which lat-eral canals are prepared using ultrasonic fi les, commonly used for intracanal applications. Those fi les are customized by bending them to accommodate the specifi c location of the lateral canal in the case at hand. This method allows for treatment of a large variety of cases with a minimal ultrasonic tip armamentarium.This simple chair-side method for preparing an endless variety of apical ultrasonic tips will be demonstrated. A variety of cases treated with such tips will be presented and discussed, including lateral ca-nals at different challenging locations as well as apical preparations to depth far beyond what is possible with conventional retro-tips.

15.50 – 16.10

The way (not) to do endodontic micro-surgery.

Mistakes and mishaps in the procedure. Their causes,

consequences and ways to avoid them.Amir WeissmanDepartment of endodontology, Tel Aviv University, Israel

Abstract

We’ve all been shown the correct way to perform surgical endodon-tics. We all have seen perfect cases of utmost technique and - of course - favorable results. It is common knowledge that we should select the right case, make the right diagnosis, plan the correct treat-ment and carry it through uneventfully. But is it achievable in every case? The simple truth is - No!The potential to go wrong exist in every step of the treatment. Some mistakes will not infl uence the prognosis, while others might lead to failure. This presentation will review some of the most com-mon mistakes that one might do during modern apicoectomy and show clinical examples of each such mistake from the presenter’s own experience. By understanding the reasons that led to those mis-haps, we hopefully may be able to avoid them the next time.

16.10 – 16.30

Aesthetic considerations in periapical surgery Charalampos Beltes, N Economides Aristotle University, Thessaloniki, Greece

Abstract

The improvement of the rate and quality of the overall soft tissue healing in modern minimally invasive surgical procedures is relat-ed to the reduction of tissue trauma, edema and injury, in order to achieve a better aesthetic result. The assessment of treatment out-comes in periapical surgery is traditionally based on clinical, symp-toms free, criteria and radiographic parameters of healing process. Nevertheless, acceptable treatment outcomes in modern surgical endodontics are no longer possible without consideration of esthetic consequences for all involved dentoalveolar structures, including hard and soft tissues. Each step, before and during soft tissue manip-ulation in periapical surgery, should be taken under consideration, regarding the avoidance of recession and scar tissue formation, es-pecially in the aesthetic critical zone. Preoperatively, the evaluation of the periodontal conditions and soft tissue biotype of the affected and adjacent teeth, the awareness of the anatomical structures in relation with soft tissue attachment, the evaluation of the quality and type of the coronal restorations and the overall concern and clas-sifi cation of the patient regarding the aesthetic outcome of the pro-cedure are of great importance. Perioperatively, the incision type and fl ap design, the elevation and retraction of soft tissues, the reattach-ment, adaption and suturing of the fl ap, are critical for the mainte-nance of high quality in the outcome of periapical surgery. Postop-erative instructions and earlier suture removal are also important. The re-estimation of the importance of soft tissues with the addition of microsurgical instruments and magnifi cation devices in periapical surgery created a high-level of combined endodontic and periodontal surgical procedures.


17.00 / 19.00

Chairperson: Damiano Pasqualini

17.00 – 17.20

From broken fi le retrieval to periradicular lesion removal

and bone regeneration. Video case presentation.Chaniotis AntonisEndodontologist, Private Practice, Athens, Greece

Abstract

Over the past several years, the fi eld of endodontics has seen many technological improvements. The introduction of new state-of-the art instruments, improved materials and the surgical operating micro-scope has narrowed the gap between the biological concepts of foun-dational dentistry and the ability to achieve consistently successful clinical results in non surgical and surgical Endodontics. Moreover, improved imaging and documentation techniques changed perma-nently our educational abilities. In this full HD video presentation, the non-surgical and surgical procedures used for the treatment of a through and through periapical lesion are presented step by step. The use of a new biphasic calcium sulphate bone graft material substi-tute (Bond BoneTM) in periradicular surgery is also discussed.

17.20 – 17.40

Endodontics versus implantology: the rationale for a

correct choice

Lorenzo Comin Chiaramonti, Alessandro Cucchi, Giacomo Cavalleri Institute of Maxillofacial surgery and Dentistry, Departement of Endodontics, University of VeronaResident, Institute of Oral surgery and Dentistry, University of Milan, Italy

Abstract

Background: One of the problems during the defi nition of a patient’s treatment plan is certainly the choice between conservation and ex-traction of a tooth element: the fi rst often means a congruous root canal treatment or retreatment, and the second involves an implant treatment. In both cases, the prosthetic restoration is necessary.Objective: The authors’ objective is to assess the cost-effectiveness for endodontic treatment/retreatment compared to the cost-effec-tiveness for osseointegrated implant, showing the key factors in the choice of the most appropriate treatment plan.Materials and Methods: The authors report the main indications and controindications to endodontic and implant treatment, underlining the current guidelines of the scientifi c literature in endodontics and implantology. In addition, the authors show different clinical cases, in which the initial conditions of the teeth involved a diffi cult choice between the maintaining or the extraction of the elements. The suc-cesses and failures of endodontic treatment/retreatment were com-pared with the successes and failures of the implant treatments in order to determinate which treatment is more predictable in the case of severely compromised teeth. Results: Both treatments can be considered available and predict-able. The implant treatment is the easiest and the fastest solution, be-cause it is independent from the initial conditions of the tooth.However, the endodontic treatment/retreatment should be the fi rst choice treatment, because it allows you to postpone the implant ther-apy, which is obviously more invasive and more risky.






32

17.40 – 18.00

Maxillary sinus vascularisation and endodontic surgical

approach for periapical lesions involving the sinus cavityGabriele Rosano, Silvio Taschieri, Tommaso Weinstein, Igor Tsesis, Massimo Del FabbroDepartment of Health Technologies, IRCCS Istituto Ortopedico Galeazzi, University of Milan, Milan, Italy The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel

Abstract

Objectives. To investigate the location of the anastomosis between the dental branch of the posterior superior alveolar artery (PSAA), known as alveolar antral artery (AAA), and the infraorbital artery (IOA) with respect to the root tips of maxillary second premolars and molars. To describe the maxillary sinus management during endodontic surgery involving maxillary second premolars and molars with periapical le-sions overlapping the sinus cavity. Material and methods. The fi rst part of the study consisted of 50 CBCT scans from patients scheduled for endodontic surgery in the posterior maxilla. The second part of the study was a series of 10 periapical surgeries where only maxillary second premolar and mo-lar roots invading the sinus were taken into consideration.Results. A bony canal, representing the course of the AAA, was de-tected in the width of the anterior lateral wall of the sinus by CBCT examination. The distance from its lowest point to the apices of maxil-lary premolars and molars was measured and found to be decreased when considering root tips and lesions encroaching the sinus fl oor. Even if the transection of such artery is not life-threatening, in such cases, impairment in visualization of the surgical fi eld as well as the laceration of the Schneiderian membrane may occur.Conclusions. A sound knowledge of the maxillary sinus vascular anatomy and its careful analysis by CBCT scan is mandatory to pre-vent complications during endodontic surgery interventions involving this region. Moreover, when performing apicoectomy of roots over-lapping the sinus cavity, attention should be paid in avoiding gutta-percha particles, drilling dust or bacteria to spread within the maxil-lary antrum using a resorbable collagen membrane as protector.

18.00 – 18.20

Fiber post adhesion: new protocols offer predictable

results Marco Scansetti, Riccardo Rota, Elio Berutti Department of Endodontics – Prof. E. Berutti, University of Turin Dental School, Turin, Italy

Abstract

Restoration of endodontically-treated teeth with adhesive materials and fi ber posts is a common clinical procedure. Bonding between fi -ber post, root dentin and adhesive resin cement, and cement durabil-ity, are essential for longevity of the post-endodontic restorations; however, root dentin is a very unfavorable substrate for adhesion. In order to achieve a satisfactory hybrid layer, the smear layer and end-odontic debris must be removed from the canal walls and from the initial part of the dentinal tubules, so as to increase the retention of adhesive materials. Various total-etching and self-etching adhesive systems are available for bonding to root dentin, but none of these may be considered perfect. Different resin cements can be employed for fi ber post cementation, including the recently-introduced self-adhesive approach. Debonding of the fi ber post, or adhesive failure, is commonest clinical failure in fi ber-post retained restorations. This presentation, describing in vitro and in vivo studies conducted at the Dental School of Turin, focuses on the pros and cons of different ad-hesive systems. SEM analysis and push-out test results assess the effi ciency of different etching protocols. New protocols for applying total-etching and self-etching adhesives improve cement-dentin bond strength. Traditional dual-curing resin cements are compared to new self-adhesive cements. Video material demonstrates the

step-by-step clinical application of traditional and new protocols, for even more predictable results.

18.20 – 18.40

The root resorption. Surgery.Massimo CalapajItaly

Abstract

The author present two clinical cases (one of internal resorption and one of external resorption ) showing step by step all the clinical procedures by video. The author will also show a brief description of the aetiology and the characteristics of root resorption, focusing his attention on the diagnosis, the treatment plan, and the most appro-priate surgical approaches and procedures than can be selected for each one of the cases, by showing two movies: one with the surgery performed on a case of internal resorption and the other one per-formed on a cese of external resorption.

18.40 – 19.00

Detection of vertical root fractures with the use of cone

beam computed tomography scans Maria Elissavet Metska, PR Wesselink, AR OzokAcademic Center of Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Amsterdam, The Netherlands

Abstract

The primary aim of this study was to assess the accuracy of cone beam computed tomography (CBCT) scans in detecting vertical root fractures in endodontically treated teeth. The secondary aim was to compare the accuracy of CBCT scans with that of periapical radio-graphs in detection of vertical root fractures. In the study were included 11 cases of endodontically treated teeth with suspected vertical root fractures. All cases had one or more of the clinical and/or radiographic signs related to vertical root frac-tures. The CBCT scans were made with the Accuitomo 3D (90 KV, 5 mA; J. Morita, Kyoto, Japan). The scans were made according to the manu-facturer’s recommended protocol, and the smallest fi eld of view FoV(40 x 40 mm) was selected. The size of the isotropic voxel was 0.08 mm. The periapical radiographs were made with a fi xed x-ray unit (Siemens Heliodent MD, Erlangen, Germany) and size 2 phos-phor-plate fi lms (Digora, Tuusula, Finland) following manufacturer’s recommendations. Two radiographs were made per tooth, one using parallel technique and the other with mesial angulation. All images were examined by two calibrated endodontists who were experienced in reading CBCT scans. The images were interpreted in three different planes, axial, coronal and sagittal. A vertical root frac-ture was considered as a radiolucent line that traversed the trunk of the root separating it either partially or completely into two segments that is followed on at least two consecutive slices. The fi ndings of inspection with an operating microscope during re-treatment, periapical or exploratory surgery, or extraction, served as gold standard. The sensitivity, specifi city and accuracy for both radiographic tech-niques were evaluated. The overall accuracy of the CBCT was higher than that of periapical radiographs, in detecting vertical root frac-tures.



ROOM LEONARDOFRIDAY, 16TH SEPTEMBER 2011

8.30 / 18.40

8.30 / 10.30

Chairperson: Lucio Daniele

8.30 – 8.50

Histological assessment of new endodontic cement after

direct pulp capping on rats molarsKhalil Issam, Toni Sarkis, Alfred Naaman Saint Joseph University Dental School

Abstract

MTA (Mineral Trioxide Aggregate) is widely used as a pulp capping agent that allows growth, proliferation and differentiation of mes-enchymal cells in pulp tissue leading to formation of active odon-toblasts to secrete tertiary dentin. Nevertheless, one of its most re-ported drawbacks is its complexity in handling and placement (sandy consistency) and its slow setting time which necessitates another appointment for the fi nal restoration. A new endodontic material, the MPC (Modifi ed Portland Cement) shows similar biological properties to MTA with easier clinical handling (putty consistency) and faster setting time. The purpose of this study was to compare the histologi-cal pulp tissue response of intact maxillary rats molars after direct pulp capping with MPC and MTA. Under general anesthesia, access cavities were prepared on the fi rst two maxillary molars of twenty 5-months-old rats. In a group of 10 rats, the pulp remnants were protected with MPC and in the other group of 10 with MTA. The cavi-ties were fi lled with composite. Animals were sacrifi ced after one, two and four weeks and the specimens removed and prepared for histological evaluation by means of light microscopy. Both materials demonstrated the same results when used as pulp capping materi-als, inducing hard tissue bridge formation and maintaining pulp vital-ity in all specimens.

8.50 – 9.10

The effect of EDTA and MTAD solution on the wettability

of crown dentine surfaceEmre Altundasar, Isl Gercek Beskardes, Hatice Dogan Buzoglu, Zafer Cavit Cehreli, Menemse GumusdereliogluHacettepe University, Faculty of Dentistry, Department of Endodontics, Ankara, TurkeyHacettepe University, Faculty of Chemical Endineering, Ankara, Turkey-3Hacettepe University, Faculty of Dentistry, Department of Pedodontics, Ankara, Turkey

Abstract

Aim:To evaluate the effect of EDTA and MTAD solutions alone or com-bined with NaOCl on the wettability of crown dentin surface. Methodology:Crowns of 42 extracted wisdom teeth were removed from cemento-enamel junction and roots were discarded. The crowns were horizontally sectioned into two similar segments to ex-pose crown dentine surfaces. One of the exposed dentinal surfaces was used as control while the other dentinal surface was treated with one of the following experimental solutions:17% EDTA alone,EDTA + 2.5% NaOCl,MTAD alone,1.25% NaOCl + MTAD,1.25% NaOCl alone and2.5% NaOCl alone.Surface free energies of samples were calculated by measuring the contact angles of both control and treated surfaces with three differ-

ent solutions. Surface tension measurements of experimental solu-tions were also performed with pendant drop method. The results were statistically analyzed by Paired-t test, One-Way Anova followed by Tukey HSD test at 95% level of signifi cance.Results: Single use of MTAD and EDTA signifi cantly decreased the surface free energy of crown dentin compared to control samples (p<0.05). Although combined use of NaOCl with EDTA and MTAD in-creased the surface free energy level of dentin surface when com-pared to single use of EDTA and MTAD solutions, the results were still lower than surface free energy level of the control.Conclusions: The use of EDTA and MTAD decreased the wettability of crown dentin surface. It may be suggested that combined use of EDTA and MTAD with NaOCl may increase the adhesive quality of these solutions.

9.10 – 9.30

Determining the corrosion rates of rotary Ni-Ti

instruments in different irrigantsDilek Dalat, Mehmet Can Göktas, Sema BilgicDepartment of Endodontics.Faculty of Dentistry, Ankara University, Ankara, TurkeyDepartment of Physical Chemistry, Faculty of Science, Ankara University, Ankara,Turkey

Abstract

The purpose of this present study was to evaluate and compare the electrochemical corrosion rate of Ni-Ti rotary fi les when immersed in EDTA,citric acid and MTAD.In this study, Protaper S2 Ni-Ti instruments were used and were im-mersed in 17 %EDTA,10% Citric Acid and MTAD irrigants. Corrosion rates of rotary fi les were determined electrochemically by the Tafel extrapolation method. Data was obtained with a potentiostat, a volt-age scan generator and a recorder. The irrigants were fi lled into a py-rex glass cell. Cutting fl utes of fi les were immersed to the irrigants. A saturated calomel electrode was used as a reference and a platinum plate was used as a counter electrode. Temperature of athmosphere was fi xed with a water engine and a thermostate. All corrosion po-tentials were determined according to reference electrode. In the experiments, current-potential curves were obtained and corrosion rates were determined with Tafel extrapolation method. Three exper-iments were performed for each irrigant and statistical analysis of the data were performed by using the Kruskal -Wallis one-way test. According to the results of this study, corrosion rates of Ni-Ti rotary fi les immersed in irrigation solutions were found 17%EDTA>10% Citric acid>MTAD respectively. Additionally according to statis-tical analysis,signifi cant difference is obtained within all three solutions(p=0.027).

9.30 – 9.50

In vitro evaluation of marginal leakage using various

temporary fi lling materialsAU Eldeniz, Bilge Akbulut Makbule, MBGuneserDepartment of Endodontics, Selcuk University, Konya, Turkey

Abstract

Aim: To compare the marginal leakage of the various temporary re-storative materials Kavitan Plus (SpofaDental, Czech Republic), IRM (Dentsply, U.S.A), Cavit-G (3M ESPE, Germany) Alganol (Kemdent, UK) and Kavitan LC (SpofaDental, Czech Republic) using a methylene blue dye penetration test.Methodology: Ninety one intact, extracted human molars were col-lected and divided into 5 experimental (n=15) and two control groups as positive and negative controls (n=8). Standardized access cavities having 4x4 mm in size were prepared in experimental and positive control samples. The access openings of the teeth in the experimen-tal groups were fi lled with approximately 5 mm of one of the test ma-terials. After material setting for 10 h, thermal cycling for 500 cycles (5°C-55°C) were applied and all teeth were stored in methylene blue






34

dye at 37°C for 7 days. Intact molars were kept as negative controls and had no cavity preparation. Access cavities in the positive control samples had no restoration. The teeth were sectioned mesiodistally with a diamond saw under water cooling and linear depth of dye pen-etration was measured in milimeters using a calibrated stereomi-croscope from the two side of restoration-tooth interface. The mean value of the dye penetration was calculated from two readings and used for statistical analysis. One way ANOVA and Tukey HSD tests were done.Results: Positive control sections exhibited complete dye penetra-tion, whereas negative controls had none. One way ANOVA and Tukey analysis indicated signifi cantly less leakage (p<0.05) with Kavitan LC compared with other tested materials. There were no statistically signifi cant difference between Cavit G, Alganol, Kavitan Plus and IRM groups (p>0.05).Conclusion: Within the limitations of this in vitro study it can be con-cluded that Kavitan LC could be more preferable by clinicians as a temporary fi lling material due to its better sealing properties.

9.50 – 10.10

The effect of different root canal sealers on the bond

strength of different fi ber post systemsNimet Gencoglu, Mustafa Gundogar Turkey

Abstract

Aim: To compare the marginal leakage of the various temporary re-storative materials Kavitan Plus (SpofaDental, In the present of this study, the effect of resin based sealers and eugenol based Kerr sealer on the bond strength of different fi ber post systems were evaluated.One hundred and twenty maxillary anterior central extracted human teeth were used in this study. The roots were seperated and adjusted to 18 mm. The roots were instrumented by using Protaper rotary sys-tem. Specimens were randomly divided into four groups and obturat-ed by using lateral condensation of gutta-percha with four different root canal sealers (AH Plus, Kerr, Epiphany, Endorez). After 7 days, teeth in each group (n=10) were received three differ-ent fi ber posts systems (DT Light, Transluma, Everstick) with Duolink resin cement. Then, the roots were embedded in acrylic resin blocks. After this period, the specimens were sectioned in three slices (api-cal, middle, coronal). The push-out test was performed in a universal testing machine. All samples submitted push out test were examined under stereomicro-scope. Data were submitted ANOVA and Tukey test. Teeth obturated with AH Plus and received DT Light fi ber post system showed the highest bond strengths (p<0.05). Teeth obturated with Kerr pulp canal sealer and Transluma fi ber post system showed the lowest bond strengths (p<0.05). Teeth obturated with Endorez and received Everstick fi ber post system showed the highest bond strengths (p<0.05).

10.10 – 10.30

A comparison of ex vivo cytotoxicity of two novel end-

odontic root canal sealersEsra Guven Pamukcu, ME Yalvac, MB Kayahan, H Sunay, F Sahin, G Bay Yeditepe University,Faculty of Dentistry, Istanbul,TurkeyYeditepe University,College of Engineering and Architecture,Istanbul,Turkey

Abstract

he aim of this study is to compare the cytotoxic effects of three end-odontic sealers to human tooth germ stem cells (hTGSCs). MTA Fil-lapex, a sealer based on MTA, was compared with iRoot SP, a bio-ceramic sealer and AH Plus Jet, an epoxy resin-based root canal sealer. Tefl on disks with a diameter of 4 mm and a height of 3 mm were prepared with these materials and were allowed to set in a hu-midifi ed 95% air atmosphere of 5% CO2 for 24 h at 37 °C. Then, these disks contacted indirectly with hTGSCs by the aid of 24 transwell per-

meable supports which had 0.4 μm pore size. The cellular response was analyzed using MTT assay after the sealers set completely. The cytotoxic effects of the materials were tested at 24 hours, 72 hours, one week, and two weeks. The results showed that iRoot SP and AH plus jet were noncytotoxic at 24 hours interval, whilst MTA Fillapex was slightly cytotoxic. AH Plus Jet was more toxic than iRoot SP after two weeks. MTA Fillapex showed severe toxicity at all intervals after 24 hours when compared with other materials. In conclusion, using both iRoot SP and AH Plus Jet seems adventagous over MTA Fillapex as a root canal sealer.


11.00 / 13.00

Chairperson: George Huang

11.00 – 11.20

Infl uence of calcium hydroxide on the root canal seal by

means of capillary fl ow porometry Moinzadeh Amir Teymour, RJG De Moor, MAA De Bruyne Ghent University, Dental School, Department of Restorative Dentistry and Endodontology

Abstract

AIM. To evaluate the short- and long-term seal of root canal fi llings with and without the placement of calcium hydroxide as an inter-mediate dressing and to compare the effect of 2 different fl ushing techniques for the removal of calcium hydroxide on the seal of the root canal obturation. METHODOLOGY. Forty-fi ve untreated palatal roots of maxillary human molars were selected and divided into 3 groups. In group 1 cleaning, shaping and obturation were performed in one session. Group 2 was treated as group 1, but obturation was performed 1 week later, with placement of calcium hydroxide in be-tween. The calcium hydroxide was removed by conventional rinsing. Group 3 was treated similarly to group 2, but the calcium hydroxide was removed using passive ultrasonic irrigation with the intermittent fl ush technique. All roots were instrumented with stainless-steel hand fi les using the balanced force technique and irrigated with NaO-Cl and EDTA. The technique of obturation was cold lateral condensa-tion with standardized gutta-percha points and an epoxy-resin sealer. One week later all samples were submitted to capillary fl ow porom-etry to assess minimum, mean fl ow and maximum pore diameters. Six months later the measurements were repeated. The results were evaluated using non-parametric tests, the level of signifi cance being set at 0.05. RESULTS. No signifi cant differences were found between the three groups for minimum, mean fl ow and maximum pore di-ameters one week after obturation time and neither at six months. CONCLUSION. Under the conditions of the present study, the place-ment of calcium hydroxide as temporary medication did not infl uence the seal of the root canal obturation. Neither did the technique used to remove the calcium hydroxide have a signifi cant infl uence on the seal of the fi nal root canal obturation.

11.20 – 11.40

Analysis of temperature rise with and without water

irrigation during metallic post removal Carolina Villasenin Sanchez, Purifi cacion Varela Patino, Jose Bahillo Gonzales, Berta Rivas Mundina, Manuel Ruíz Pinon, Benjamin Martín Biedma Master de Endodoncia, Universidad de Santiago de Compostela, Spain

Abstract

Methods: thirty maxillary molars were randomly divided into three groups. Root lengths were standardized; palatal roots were instru-mented and obturated. Metallic posts were cemented 8 mm in depth. Thermocouples were connected to a precision thermometer and po-



sitioned at two locations on the palatal root surface with a fi xed dis-tance between them (one was at the cementoenamel junction and the other was 6 mm in apical direction). Teeth were submerged in water controlled at 37ºC by a thermostat. In group 1, posts were removed with Proultra tips without irrigation. Group 2, StartX without irriga-tion. Group 3, StartX with water irrigation every 20 seconds of work. Temperatures were recorded and stored in a computer software at intervals of 30 seconds.Results: temperature differences were observed between StartX and Proultra groups, temperature increase more in group 2. In all groups temperature rise was higher at the cementoenamel junction.Conclusions: StartX ultrasonic tips, that incorporate water coolant, proved to be more effective in reducing temperature rise during re-moval of metallic posts.

11.40 – 12.00

In vitro evaluation of the antimicrobial activity of several

self-etching adhesive systems against Enterococcus

faecalis David Rubio Flores, V Vera Gonzalez, E Garcia Barbero, AE Garcia Barbero Department of conservative dentistry. Complutense University of Madrid, Spain

Abstract

AIM: Determine in vitro the antimicrobial activity of fi ve self-etching adhesive systems: Futurabond DC® (Voco), Adhe SE One® (Ivoclar Vivadent), Xeno III® (Dentsply), Clearfi l Protect Bond® (Kuraray) and G- Bond® (GC) , and 2% clorhexidine as positive control and conventional adhesive system Excite® (Ivoclar Vivadent) against the endodontic pathogen Enterococcus faecalis. HYPOTHESIS: Consider the ability of the new self-etching adhesive systems not only as a sealant but also as an inhibitor agent for bacteria located in pulp ne-crosis. METHODOLOGY: 1.Mac Farland technique. 2. Bacteria plated over Brain Heart Infusion (BHI) agar plates (10 for each adhesive system and each bacteria). 3.Placing of susceptibility paper discs (SensiDisc®) containing the adhesive. 4.Incubation at 37º C for 48 hours. 5.Taking photos with optic microscope. 6.Measuring of zones of growth inhibition with Image Tool 3.0. 4 points were measured for each agar plate. 7.Data statistical analysis (One- way ANOVA). RE-SULTS: One- way ANOVA showed results statistically signifi cant (p < 0,0001), with Clorhexidine 2% as the most inhibitor agent, followed by Futuranbond DC®, Clearfi l Protect Bond®, Xeno III®, G- Bond®, Adhe SE One® and Excite® with differences statistically signifi cant among them. CONCLUSION: Self- etching adhesive systems are po-tentially inhibitory agents for Enterococcus faecalis.

12.00 – 12.20

Effi cacy of Mineral Trioxide Aggregate in direct pulp

capping on adult patients: clinical study Lucio Daniele, M Tieri Private Practice, L’Aquila, Italy

Abstract

The preservation of pulpal vitality is particularly important where mechanical, traumatic or decay pulpar exposures occur, especially in teeth with a radicular formation still in progress. Mineral Trioxide Aggregate (MTA) has good physical and chemical properties, excel-lent biocompatibility, excellent sealing properties, antibacterial ef-fects and offers a good performance even in the presence of fl uid contamination of the operating area. For this reason it is used for several clinical applications in dentistry. One of these applications is on direct pulp capping favouring the formation of calcifi ed and hard tissue on its surface.The aim of this study is to evaluate from a clinical point of view the MTA performance in pulp capping.76 asymptomatic elements and 4 symptomatic, with exposed pulp due to curettage in the decay cavity, were treated with MTA. After

isolating the operating area with rubber dam, cleaning the decay cav-ity and waiting for a light bleeding to stop (only in some cases), the exposed pulp was covered with a MTA layer of 2-3 mm, wet cotton and temporary material. One week later, we removed the temporary fi ll-ing and checked the effective hardening of MTA. In the same session we proceeded to rebuild the tooth using dental enamel bicomponent adhesive and composite resin fi lling. Clinical and radiographic controls were planned for a period of 12 to 48 months; some elements have been controlled for 7 years. Afterwards, only 4 of the 80 cases treated required endodontic treat-ment, none of them was symptomatic; in all successful cases no cal-cifi cation or reabsorption occurred. In our clinical research, we had a success percentage of 95%.In conclusion, the study suggests a successful use of MTA for direct pulp capping in permanent teeth to preserve the pulp vitality. Further histological investigation is needed to support these fi ndings.

12.20 – 12.40

Infl uence of powdered-dentin addition to primer or

adhesive on shear-bond-strength of sealers to root-dentiSema Belli, Melek Akman, Betül Özçopur, Gürcan Eskitacolu Selcuk University Faculty of Dentistry Endodontics Konya Turkey and Yuzuncu Yil University Faculty of Dentistry Endodontics Van Turkey

Abstract

Aim: To investigate the effect of powdered-dentin addition to primer or adhesive of a self-etch system on shear bond strength of three resin based sealers to root-dentin.Methodology: 72 extracted premolars were sectioned buccolingually and 144 root halves were randomly divided into three groups accord-ing to the sealer (AH Plus, Real Seal, Hybrit Root SEAL, n=48). The cut surfaces were ground and pretreated with 5% NaOCl and 17% EDTA solutions for 5 minutes followed by 5 minutes of distilled wa-ter irrigation. Four subgroups according to the testing procedure, n = 12: 1: Control groups, 2: Clearfi l Liner Bond 2V treated groups; 3: Powdered dentin added to the primer of Clearfi l Liner Bond 2V (40wt. %); 4: Powdered dentin added to the bonding of Clearfi l Liner Bond 2V (20wt. %). Dentin particles were prepared by sieving through fi ne-mesh screens with 5μm size. Three mm high build-ups with a con-stant surface area of 3.14 mm2 were created using the sealers and allowed to set (37ºC, 100% humid, 72 hrs). The samples were tested to failure for shear bond strength (1 mm/minute). The data was cal-culated (MPa) and analyzed using Two-way ANOVA, Tukey HSD and Independent-T tests, sig. 0.05).Results: There were statistically signifi cant differences in the shear bond strengths values of the tested endodontic sealers (P < 0.05). AH Plus showed statistically higher bond strength than Real Seal and Hybrid Root SEAL (P < 0.05). Powdered-dentin addition to primer or adhesive had no effect on shear-bond-strength of sealers to root-dentin (p>0.05).Conclusions: Results of this study suggested that powdered-dentin addition to primer or adhesive did not alter the shear bond strengths of resin based sealers to root-dentin.

12.40 – 13.00

Infl uence of the fi nal apical taper on the sealing ability

of Real Seal1 v/s Thermafi l: a three-dimensional in vitro

study Carla Zogheib, Alfred Naaman, Reza Arbab-Chirani School of Dentistry, Saint-Joseph University, Beirut, LebanonSchool of Dentistry, Bretagne Occidentale Universit , Brest, France

Abstract

The aim of the study was to measure percentage of volume of voids and gaps in the apical third of root canals obturated with two carrier-techniques obturation materials with three different fi nal preparation tapers (4%, 6%, 8%) using micro-computed tomography (micro-CT).






36

Fifty-four single-rooted teeth were collected and decoronated, and root canals were prepared by using rotary fi les. The roots were ran-domly allocated into 3 groups, and each group was obturated by us-ing thermoplasticized technique with a different material (gutta-per-cha and Topseal for Thermafi l, Resilon and RealSeal for Real Seal1). Roots were scanned with micro-CT, and volume measurements for voids and gaps in the obturated roots were carried out using special-ized CT software. Percentage of gaps and voids was calculated.The present study showed that none of the root canal fi lled teeth were gap-free. Two-way ANOVA followed by univariate tests and SIDAK pairwise comparisons were performed to explore signifi cant differ-ence between groups. Roots fi lled with thermafi l showed less voids and gaps than roots fi lled with Real Seal 1. Among materials, voids mean percentage was signifi cantly higher with Real Seal 1 taper 0.04 (p value =0.05).There was no signifi cant difference with 0.06 and 0.08 fi nal taper. There was no signifi cant difference with Thermafi l (p-val-ue> 0.05) between the 3 different fi nal tapers. Final taper 0.08 fi lled with both materials showed less voids and gaps than the two other fi nal tapers.

13.00/14.30 LUNCH

14.30 / 16.30

Chairperson: Marco Ferrari

14.30 – 14.50

Infl uence of image acquisition parameters on CBCT

endodontic recostructions Jerome Michetti, JP Mallet, L van der Sluis, F Diemer, K Boulanouar INSERM U825, Toulouse, FranceUniversity of Dentistry, Toulouse, France

Abstract

INTRODUCTION: Cone-beam computed tomography could provide 2D or 3D high quality images of the root canal anatomy. They appear to be powerful complementary radiologic imaging tools, which can help endodontic diagnosis and treatment. Nevertheless, the preci-sion of these images depends on the imaging system used (resolu-tion and reconstruction of the volume) but also on the image acquisi-tion settings.AIM: The aim of this study is to evaluate the infl uence of image ac-quisition parameters on CBCT endodontic reconstructions in order to improve the accuracy of measurements of the root canal anatomy.METHODS: Eleven intact teeth with closed apexes were scanned us-ing the “9000 3D®” (76μm, 14 bits) by using different combinations of acquisition settings. 3D images were displayed with the KDIS software (v 3.8) and root canals were segmented. Before the acquisition, roots were perpendicular sectioned to the radicular axis, at predetermined levels and parallel to a 2D reference point. Histological root canal sec-tions were then digitized with a 0,5 to 1μm resolution and compared with equivalent 2D cone-beam reconstructions: areas and Feret’s di-ameter of the root canal outlines were calculated for each section.RESULTS: 4mA and 60kV association provided the best results con-cerning the endodontic reconstructions.CONCLUSIONS: Accuracy of the measurements from CBCT images greatly depends on image acquisition parameters used, which also depend on the software used to reconstruct volumes after acquisi-tion.It appears necessary to evaluate, in future research, the infl uence of endodontic segmentation methods and parameters.

14.50 – 15.10

Technological evolution of fi ber postsGiovanni CavalliPrivate practice, Brescia, Italy

Abstract

Since their introduction during the second half of the 90s up to today,

fi ber posts have been subjected to various modifi cations, fi rst of all in shape, in the surfaces, in fi brous materials and in the resinous fi ller components.Sometimes it has been a matter of a commercial or marketing change without improvement of performances, some other times it was an attempt of making improvements which have actually deter-mined clinicial advantages.Currently fi ber posts are available, built with different fi bers, and they are used in different clinicial conditions: carbon fi bers are suitable in case of high load; white fi bers (glass or silica) in case covering mate-rials not completely opaque are used; traslucent posts are necessary if photo-cured or dual-cured cements are used; different conicity of endodontic preparation of the channel implies posts with appropri-ate conicity; posts with poiligonal or ellittic section are suitable for canals with elliptic or ovoidal section; some resins of the fi lling part of the post give a better bonding with cement; to improve adhesion between post an cement , the surface of the posts is treated to obtain a very rough and microrententive surface; posts can be personalized if built with preimpregnate fi bers; a new seam is recently developing with the introduction of a weak central support that allows to have a guide for an easier removal of the pivot when it is necessary.The purpose of this restorative technique, which spread out really quickly (and successfully), is to bring in the canal the greatest num-ber of fi bers and to get the best bond between post and cement. The correct mechanical properties of cement (Young’s module similar to the one of the post) are also very important in order to obtain the bet-ter performance of post itself.

15.10 – 15.30

Effect of ozone application on the shear bond strength of

resin cements to nonvital bleached dentinBetul Ozcopur, Eylem Ayhan Alkan, Eraslan Oznur, Devrim Akyol, Gurcan Eskitascioglu, Sema BelliYuzuncu Yil University, Faculty of Dentistry, Department of Endodontics,Van,Turkey - Selcuk University, Faculty of Dentistry, Department of Endodontics,Konya, Turkey

Abstract

Aim: To evaluate the bond strengths of two resin based cements bonded to ozon-treated or non-treated nonvital bleached dentin.Methodology: Eighty freshly extracted sound human maxillary inci-sor crowns were assigned to eight groups (n = 10): (G1, G2) bleached (10% carbamide peroxide, Opalescence) without or (G3,G4) with ap-plication of gaseous ozone (40%, 50 second, CR probe, Biozonix; High-Frequency Ozone Generator, Germany), (G5, G6) ozon treated without bleaching and (G7, G8) untreated control groups. The crowns were embedded in acrylic resin and dentin surfaces were exposed. Specimens were bonded with one of the two resin cements: Secure Cement (Sun Medical) (G1, G3, G5, G7); Clearfi l Esthetic Cement (Ku-raray) (G2, G4, G6, G8). Three x 3 build-ups were created with the Resin cements and allowed to set (37ºC, 100% humid, 24 hrs) and then tested to failure for shear bond strength (1 mm/minute). The data was calculated as MPa and analyzed using Kruskal-Wallis test (P < 0.05).Results: Combination of ozone treatment and bleaching resulted in increased bond strength on both Secure cement (G3) and Clearfi l Es-thetic cement (G4) specimens (p > 0.05). Secure cement specimens treated with ozone (G5) demonstrated signifi cantly lower shear bond strengths than G1, G3, and G7 (P < 0.05). Signifi cant increase in shear bond strength was detected in Clearfi l Esthetic cement group (G4) when compared to untreated control group (G8).Conclusions: Pretreatment with ozone prior to bonding procedure may decrease the effect of residual peroxide-induced reduction in resin bond strength. Thus, Ozone application on nonvital bleached dentin surfaces can improve resin cement bonding to dentin surfaces.



15.30 – 15.50

An in-vitro and in-vivo evaluation of a new calcium-

silicate based dentine substituteGiulia Ferrara, Silvio Taschieri, Massimo Del Fabbro, P. Machtou Università degli Studi di Milano, Milano, Italy. Université Paris-Diderot, Paris, France

Abstract

Materials and methods: 1- Clinical evaluation: Correct endodontic in-dications of this class of calciumsilicate cements have been clinically evaluated at one year follow up. 2- In Vitro evaluation: 15 maxillary anterior teeth deriving from 5 fresh human cadavers underwent end-odontic treatment and apical resection in situ. In two groups retro-grade cavities were prepared using ultrasonic retro-tips and subse-quently 10 teeth (5 per group) were fi lled with Biodentine (Septodont, UK), using 2 different setting time (Group B1 as recommended by the manufacturer, Group B2 5 sec. less) and 5 teeth were used as control group and fi lled with MTA . Each root was duplicated and analyzed by Scanning Electron Microscope for the presence of root fi lling gaps (marginal adaptation). Results: 1- In vivo: Given the similarity of their composition and properties, many clinical indications of the material overlap with those for MTA: direct pulp capping, obturation of radicu-lar perforations, retrograde endodontic obturation. 2- In vitro: The number of gaps was signifi cantly higher in the group where the set-ting time was not respected. Using the setting time recommended by the manufacturer the material showed excellent mechanical prop-erties and root-end cavity sealing ability. Conclusions: Biodentine (Septodont, UK) can be considered a suitable dentine replacement material whenever original dentine is damaged. Additional quanti-tative and histological studies with larger samples size and longer follow-up duration are needed to confi rm the results of this study.

15.50 – 16.10

Mineralization of odonotoblastic-lineage cells accelerated

by enhanced expression of Mef2cNobuyuki Kawashima, Jing Xu, Noriyuki Suzuki, Mengyu Zhou, Kouy-ou Takimoto, Yu Koizumi, Mioko Yamamoto, Satomi Takahashi, Toshi-hiro Sugiyama, Hideaki SudaDepartment of Conservative Dentistry. Complutense University of Madrid, Spain

Abstract

Aim. Differentiation/mineralization of odontoblasts is regulated by various factors. We revealed that the Myocyte (-Specifi c) enhancer factor 2c (Mef2c), a major transcriptional factor, along with MyoD and Mif5, in the myoblast differentiation, was strongly expressed in rat and human mature odontoblasts. Our fi nding suggests that Mef2c may be not only a master gene of myocyte differentiation but also one of the regulator genes of odontoblast differentiation/mineralization. The purpose of this study was to evaluate the effects of enhanced expression of Mef2c on the mineralization and the odontoblast dif-ferentiation in the odontoblast-lineage cells.Methodology. Odonotoblastic-Lineage Cells (OLCs) were cultured in alpha-MEM supplemented with 10% FBS (HiClone) and antibiot-ics. ORF of the Mef2c cDNA clone (MGC:25468) was inserted into pEF DEST51 (mammalian expression vector) using Gateway system (Invi-trogen). pEF Mef2c and a mock vector (pEF EGFP) were transfected into OLCs, and stable lines (OLC-Mef2c and OLC-Mock) were selected using specifi c antibodies (Blasticidin). Nodule formation was induced by ascorbic acid (0.2 mM) and beta-glycerol phosphate (5 mM), and de-tected by alizarin red staining. Expressions of osteoblastic/odontoblas-tic markers were evaluated by real-time PCR using specifi c primers.Results. OLC-Mef2c showed a high capacity of mineralized nodule formation compared to OLC-Mock. Expressions of osteoblastic/odon-toblastic markers were highly up-regulated in OLC-Mef2c. These results indicate that Mef2c may be one of the essential factors for odontoblast differentiation/mineralization.

Conclusions. Mef2c accelerated the mineralization and up-regulated osteoblastic/odontoblastic marker expression in the odontoblast-lineage cells.

16.10-16.30

SEM evaluation of the interphases between mineral

trioxide aggregate and composite resin and silver

amalgam David Rubio Flores, V Vera Gonzalez, E Garcia Barbero, AE Garcia Barbero Department of Conservative Dentistry. Complutense University of Madrid, Spain

Abstract

Mineral Trioxide Aggregate (ProRoot MTA®) is indicated in several clinical situations with communications between the inner and the outer structure of teeth (perforations, apicoectomies, apical plugs…) AIM: Evaluation under scanning electron microscope (SEM) of in-terphases between Mineral Trioxide Aggregate and two obturation materials: composite resin (Tetric-Evo Flow®) and silver amalgam; and the interphase with dentin. MATERIALS: Twelve natural freshly extracted teeth, Mineral Trioxide Aggregate (Pro- Root MTA®), sil-ver amalgam, fl owable composite resin (Tetric-Evo Flow®), self-etching dual-curing adhesive system (Futurabond DC®) and Scan-ning electron microscope. METHODOLOGY: Preparation of class- V cavities, obturated with MTA- layers (1- 1,5 mm thickness). Samples were immersed in distilled water for two different hydration times: 10 minutes and 48 hours. Cavities were sealed with composite resin or silver amalgam randomizely. Samples were prepared for SEM tech-nique and images obtained were analysed by Image Tool® software analyzer. RESULTS: Every interphases analysed with composite resin are sealed and closed. For 48 hours hydration time, MTA structure is completely integrated to dentin substrate. For 10 minutes hydration times, MTA- structure shows a cohesive fracture, keeping the inter-phase with dentin closed. For silver amalgam group, in both hydra-tion times, interphases are opened, showing an uneffi cient sealing. Interphases with dentin are always completely sealed and closed. CONCLUSION: Obturation of teeth with MTA- layers looks sealed when using composite resin and not when using silver amalgam. Be-sides, MTA- structure is intact when hydrating for 48 hours and not when hydrating for 10 minutes.


17.00 / 18.40

Chairperson: Elio Berutti

17.00 – 17.20

Direction of isolated dental pulp progenitor / stem cells

to form dentine Kostantinos Kodonas, C Gogos, S Papadimitriou, K Kouzi-Koliakou, D TziafasDepartment of Endodontology, School of Dentistry, Aristotle University of Thessaloniki, GreeceCompanion Animals Clinic, Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, GreeceLaboratory of Histology-Embryology, Medical School, Aristotle University of Thessaloniki, Greece

Abstract

Numerous experimental approaches have demonstrated that iso-lated Dental Pulp Stem Cells (DPSCs) can be directed to differentiate into cells of the odontoblastic lineage, forming dentine-like struc-tures and associated pulp tissue in transplants. AIM: The purpose of the present study was to review the experimen-tal data showing de novo differentiation of odontoblast-like cells.






38

METHODOLOGY: An electronic MEDLINE search was conducted to identify experimental studies relevant to stem cell-mediated dentine regeneration. Morphological, histological and immunohistochemical evidence characterizing DPSCs’ interaction with dentine were re-viewed and existing experimental models were evaluated compara-tively by introducing the hybrid root implant model. Root implants were manufactured, by seeding labelled cells onto collagen or PLGA scaffolds, fi lling pieces of root canals with the cell-scaffold con-struct and using them as root implants in the post extraction mini pig socket. The resulting constructs were evaluated by histological and immunohistochemical analyses after 2, 6 and 12 weeks. RESULTS: The regeneration of dentine-like or pulp-like tissues had been mainly elucidated by studies using subcutaneous implants of DPSCs seeded on synthetic or organic scaffolds. The absence of typical odontoblast morphology of the newly formed cells is documented. Representing the natural tooth-forming site, mandibular or maxillary jaw bone has been previously used in dental tissue engineering experiments, but never combined with transplants incorporating existing dentine surfaces. The presence of a continuous layer of cells adjacent to the newly deposited organic matrix along with the positive immu-nostaining for DMP-I and BSP-II strongly support the presence of odontoblast-like cells in the root implant bioengineered cell-dentine interface. CONCLUSION: Using the root implant model, evidence of organised extracellular matrix deposition by cells expressing appropriate pro-tein markers is presented. A synthesis of facts and hypotheses on the DPSCs lineage dynamics as well as the role of the microenvironment in regeneration of the dentine-pulp complex is further discussed.

17.20 – 17.40

Endodontic pathology and Actinomyces israelii: genomic

diagnosisBeatriz Vera-Sirera, Leopoldo Forner-Navarro, Francisco José Vera-Sempere, Ana Pellín-Carcelén.Department of Endodontology, School of Dentistry, Aristotle University of Thessaloniki, GreeceDepartament of Stomatology. Universitat of Valencia (Spain). Department of Pathology. Universitat de Valencia. Service of Pathology and Molecular Pathology Laboratory, “La Fe” University Hospital. Valencia (Spain)Molecular Pathology Laboratory. “La Fe”University Hospital. Valencia (Spain)

Abstract

Introduction. The most commonly associated factor in the lack of healing in endodontics is infection of the root canals. In this regard, the presence of Actinomyces species has been associated in some of these cases of endodontic treatment with unsatisfactory clinical outcome.Objective. Identifying the presence of Actinomyces in root canals in relation to the different pulpal and periapical pathologies.Material and Methods. 75 samples were obtained from 45 patients with a previously untreated pulpo-periapical pathology, referred for treatment within the Postgraduate Program in Endodontology at the University of Valencia. Samples were obtained using K-fl exofi les and then, DNA content were extracted from samples. Semi-nested polymerase chain reaction assay for 16S ribosomal gene of Actino-myces israelii was performed . Data obtained were processed with SPSS 1.5 software. Actinomyces israelli presence related to different pathologies was made through the Chi square test (p<0,027) Results. The molecular analysis showed a positive presence of Ac-tinomyces israelli in 61% of the samples, corresponding to 56% of our patients. In addition, we found Actinomyces israelli in 66,6 % of pulp with negative vitality, data related to our results of 86,6% of positive Actinomyces israelii in cases of necrotic root canals and also in 66,7% of apical abscesses. Conclusions. Our results show that the prevalence of this bacteria is more common than thought. Molecular analysis is a good tool to know which is the microbiological ethiology of our endodontic fail-ures, and this knowledge is useful to our clinical practice.

17.40 – 18.00

An evaluation of a modifi ed diametral compression test

for intracanal post bond strength measurement Huang Shih-hao, L Lin, AS Fok Minnesota Dental Research Center for Biomaterials and Biomechanics, University of Minnesota, Minneapolis, USA

Abstract

Introduction: Root fracture is a main failure mode in endodontically treated teeth. The risk of root fracture increased when the post is not perfectly bonded to the tooth tissues. It is therefore important to determine accurately the bond strength between the post and root canal dentin. The objective of this study was to evaluate the suitability of a modifi ed diametral compression test for measuring the tensile bond strength between posts and root canal dentin.Materials and Methods: Eighteen single-root canal teeth were end-odontically prepared and restored with a post (8 metal,8 fi ber and 8 composite) cemented with resin cement. Each restored tooth was potted into a customized cylindrical device using composite resin to form a rod, which was then sliced into 2-mm thick discs. The disc specimens were stored for 7 days before being subjected to diame-tral compression in a universal testing machine. The loading process was recorded with a high-speed camera, and digital image correla-tion (DIC) was used to identify the regions of debonding through the surface strain distribution. The fi nite element method (FEM) was also used to derive the radial and hoop stresses in the disc specimen. Results & Discussion: Large strain concentrations were detected by DIC, immediately before fracture, at the post-dentin interface where maximum radial tensile stress was predicted by the FEM. The meth-od therefore appeared to be viable for post-dentin tensi!le bond strength measurement. Compared to other test methods, specimen preparation for the new method was simpler and there was less pre-test failure. The average failure load in the Composite-post group (317N) was lower than those in the other two groups (462N for fi ber and 433N for Metal).Conclusions: The results showed that the modifi ed diametral com-pression test could be a viable method for measuring the tensile bond strength between posts and root canal dentin.

18.00 – 18.20

C-shaped canals. An old problem with an innovative

solution.Michael SolomonovBoard Certifi ed EndodontistEndodontic department Hebrew University Hadassah, Jerusalem, Israel

Abstract

C-shaped root canals present a challenge to even the experienced endodontist. The unusual ribbonshaped anatomy of these canals cannot be properly evaluated from clinical radiographs; only a 3D reconstruction from micro-CT scans reveals the large variety of morphologies that these teeth present. The extent and nature of the challenge of C-shaped root canals will be presented using such 3D images. Cleaning and shaping of C-shaped root canal system with regular stainless steel or rotary NiTi fi les is extremely ineffi cient. A recent micro-CT study reveals the limitations of traditional methods. The newly developed Self Adjustable File (SAF) system represents a new concept in root canal cleaning and shaping. The hollow fi le which is used by this system is extremely compressible and adapts itself to the cross section of even fl at-oval root canals. It is operated with a trans-line reciprocating motion (in-and-out), generated by a special handpiece head. Irrigation with a continuous fl ow of fresh sodium hy-pochlorite that goes through the hollow fi le is done throughout the shaping procedure. This new concept may be specially useful in the fl at canal systems of C-shaped root canals. A recent micro-CT study indicates that the SAF system can effectively clean and shape these challenging root canal systems.Even the most extremely fl at parts of the C-shaped root canal sys-



tems could be effectively cleaned with a uniform layer of dentin re-moved all along the canal’s cross section. Nevertheless, due to the extreme variety of morphologies that these canals present, it takes an experienced endodontist, using both a microscope and his previ-ous familiarity with typical C-shaped morphologies to make the best use of this new tool. The results of the microCT study will be pre-sented together with clinical recommendations of how to effectively use the new SAF system in C-shaped root canals.

18.20-18.40

Modern clinical approaches to post-endodontic

restorations Gilbert Gallo, Giulio Del Mastro University Dental School, Turin, Italy

Abstract

Today, the most advanced root canals shaping and fi lling techniques allow us to fully restore to function many compromised teeth which in the past would have not been recoverable. At the same time, in order to consolidate endodontic procedures’ long-term success, the demand for good quality post-endodontic restorations increases. Evidence shows that coronal leakage causes bacteria’s and toxins’ infi ltration, resulting in a complete infection of the root canal system, although properly fi lled. Nowadays, literature and clinical evidence-based research allows us to break free from the old “dogma” which forced us to always restore an endodontically treated tooth with a cast post and a crown. The new “minimally invasive” dental trend al-lows us to choose the most rational restorative technique for each case. Dental biomechanics knowledge, adhesive techniques reli-ability and carbon fi bre or glass posts have completely changed the clinical approach to post-endo restoration. If necessary, an adhesive post cementation can easily be performed at the end of the endo pro-cedures, while the rubber dam is still in place. Following the cor-rect procedures, we can reach two goals: an immediate coronal seal of the root canal system and the fi nal restoration at the same time. Strict operating procedures, moreover, have become necessary but not suffi cient conditions for the long-term success of the severely compromised tooth restoration. A multidisciplinary treatment plan is also needed, including a careful management of functional loading, aimed at reducing occlusal and masticatory stress, both functional and parafunctional. Focusing on these aspects, this presentation’s goal is to provide to the clinician useful guidelines for the choice of the best restoration suited for every post-endo clinical hypothesises, in order to achieve the best long-term results.

ROOM LEONARDOSATURDAY, 17TH SEPTEMBER 2011

8.30 / 16.30

8.30 / 10.30

Chairperson: Robert Love

8.30 – 8.50

Assessment of combined articaine and ketamine for

anesthetic effi cacy in patients with irreversible pulpitis S. Apiliogullari, FK Cobankara, Keziban Celik, Hilal Erdogan Selcuk University, Selcuklu Medical Faculty, Department of Algology, Konya, TurkeySelcuk University, Faculty of Dentistry, Department of Endodontics, Konya, Turkey

Abstract

Aim: The purpose of this prospective, randomized, double-blind pla-cebo controlled study was to assess whether the success rate of infe-rior alveolar nerve blocks (IANB) is increased by addition of ketamine to articaine in patients experiencing irreversible pulpitis in mandibu-lar posterior teeth.Methods: Seventy emergency patients diagnosed with irreversible pulpitis of a mandibular posterior tooth were randomly assigned to two groups: Group (1): 1.8 ml articaine (4% articaine with 1:100.000 epinephrine) plus 0.2 mg.kg-1 ketamine Group (2): 1.8 ml articaine plus 0.9% NaCl (placebo) for a conventional IANB. Endodontic access was begun 15 min after solution deposition, and all patients were re-quired to have profound lip numbness. Success was defi ned as none or mild pain (Heft Parker Visual Analogue Scale recordings) on end-odontic access or initial instrumentation. Results:The success rate of the inferior alveolar nerve block was 46.7% (14 of 30) and 23.3% (7 of 30) in Group (1) and Group (2), re-spectively. Two groups were statistically similar regarding the suc-cess rate of IANB (p>0.05). The rate of adverse effects in Group (1) was more than Group (2).Conclusions: Within the limitations of this in vitro study, it was con-cluded that additional ketamine at a dose of 0.2 mg.kg-1 to articaine is not improve the success rate of IANB in patients experiencing ir-reversible pulpitis in mandibular posterior teeth.Key words: Irreversible pulpitis, inferior alveolar nerve block, artic-aine, ketamine.

8.50 – 9.10

Effi cacy of supplemental intraligamentary fentanyl

injection in patients with irreversible pulpitis when the

inferior alveolar nerve block fails Prof. FK Cobankara, Prof. S Apiliogullari, Keziban Celik Selcuk University, Faculty of Dentistry, Department of Endodontics, Konya, Turkey Selcuk University, Selcuklu Medical Faculty, Department of Algology, Konya, Turkey

Abstract

The aim of this study was to compare the effi cacy of the intraligamen-tary injection of fentanyl and 4% articaine with 1:100.000 epinephrine in mandibular posterior teeth diagnosed with acute symptomatic ir-reversible pulpitis when the conventional inferior alveolar nerve (IAN) block fails. Methods: Seventy emergency patients, diagnosed with irreversible pulpitis of a mandibular posterior tooth, received an IAN block and had moderate to severe pain on endodontic access. Patients were randomly divided into two groups. The supplemen-tal intraligamentary anesthesia of a cartridge of 4% articaine with 1:100.000 epinephrine or fentanyl were administered mesial and dis-






40

tal to the tooth requiring endodontic treatment. Success of the in-traligamentary injection was defi ned as “no pain” or “mild pain” on endodontic access or instrumentation by using Heft Parker visual an-alog scale. Results: The success rate of the supplemental intraliga-mentary injection using fentanyl and articaine was 45.7% and 34.3%, respectively. There was no statistically signifi cant difference (p >0.05) between the two solutions. Conclusion: Within the limitations of this study, it was concluded that supplemental intraligamentary injection with the fentanyl did not improve the success rate over 4% articaine with 1:100.000 epinephrine solution when the IAN block fails for end-odontic procedures requiring profound pulpal anesthesia.

9.10 – 9.30

The integrated use of new technologies improve

the prognosis and the profi tability of the endodontic

treatmentRoberto SammarcoPrivate Dental Practices, Sicily, Italy

Abstract

Today, using new technologies, it is possible:• to do endodontic treatments joining the advantage of the most used tecniques : Crown-Down and Single-Lenght , using the new Hybrid Technique. With the crown-down technique we remove coronal inter-ferences working in the external part of the root and not in the inter-nal part where we have a little amount of dentinal wall, remaining in the part of the root canal where we have a large thickness of dentine. In the” Diameter “ Crown-Down technique all instruments show the same taper. Every instrument works to favour the penetration toward the apex of the instruments with the taper immediately lower. The Single-Length technique is also called “Simultaneous “ because the apex will be reached by the fi rst instrument and by all the instru-ments. These will perform 2 actions “ simultaneously”: they all reach the apex and will enlarge the root canal system. But This technique could cause a large number of complications, like stripping and ledg-es due to restoring forces and lateral cutting activity of the instru-ments.The permanence of interferences in narrow canals increases the torque on the blade of instrument, favouring the fractures. Hybrid Technique acquires all the concepts of Crown-Down, leaving out of the rule of the work in apex only after the removal of interferences , and the apex will already be reached by 02 taper instrument, to per-form the glyde path. If we leave canals partially uncleaned the risk of failure will increase by 14% per mm. not shaped. • to reduce fractures of Ni-Ti instruments with eletrochemical treat-ment, thermal nitridadion and nitrogen-ionic implantation . The ef-fect is a higher wear resistance and an increased cutting capacity. • to prepare canals while simultaneously taking measurements.

9.30 – 9.50

New equipments and microscope reduce working time

and increase safely of endodontic treatmentsSergio La RoccaPrivate Dental Practices, Sicily, Italy

Abstract

It is generally accepted that root canal treatment procedures should be confi ned within the root canal system.Root canal treatment involves removing microorganisms from within the pulp space, and the fi lling of the root canal system to prevent reinfection.The removal of all pulp tissue, necrotic material and microorganisms from the root canal is essential for endodontic success. This can only be achieved if the length of the root canal is determined with accu-racy.The outcome of treatment of roots with necrotic pulps and periapical lesions is infl uenced signifi cantly by the apical level of the root fi lling.To achieve this objective the canal terminus must be detected accu-

rately during canal preparation and precise control of working length during the process must be maintained. The prevenction of enlargement of the apex is necessary to seal it safely .With the aid of the operative microscope we have the possibility to see the inside anatomy, to reduce working time, and to prevent strip-ping, ledges and fractures of instruments.

9.50 – 10.10

Size and location of access cavity in permanent incisors,

canines and premolarsKrapez Jana, Filder AlesUniversity of Ljubljana Faculty of Medicine, Ljubljana, Slovenia

Abstract

The aim of the study was to determine the largest diameter of a root canal in the mesio-distal and vestibulo-oral dimensions and to deter-mine the position of access cavity in incisors, canines and premolars in order to defi ne the dimensions and location of access cavity.20 extracted lower and upper incisors, canines and premolars, were randomly selected and radiographed from the mesio-distal and ves-tibulo-oral direction together with a metallic reference object. Imag-es were acquired with a storage phosphor plate system and exported in image analysis software. Measurements were calibrated with the metallic reference object and position of the straight line access to apical third of a root canal and the largest diameter in mesio-distal and vestibulo-oral direction were determined for each tooth. Mean and standard deviation of diameters of each tooth group were cal-culated.The results of the study demonstrated that in lower incisors the straight line access is achieved from incisal edge (83%) and buccal surface (17%), in lower canines from incisal edge (100%), in upper central incisives from incisal edge (50%) and oral surface (50%), in upper lateral incisives from incisal edge (90%) and either buccal (5%) or oral surface (5%), and in upper canines from incisal edge (90%) and oral surface (10%). In lower premolars the straight line access is positioned buccal from central fi ssure and in upper premolars be-tween the cusp tips. The mesio-distal width was less than the dis-tance between marginal ridges.According to the results of the study it is recommended that the loca-tion of access cavity in incisors and canines is on incisal edge or the incisal half of oral surface . In premolars access cavity should not extend to marginal ridges.

10.10 – 10.30

Stress analysis of different treatment options at

hemisection of mandibular molar toothEraslan Oznur, Eraslan Oguz, Belli SemaUniversity of Selcuk, Faculty of Dentistry, Department of Endodontics, Konya, Turkey

Abstract

Objective: The purpose of this fi nite elemental analysis (FEA) study was to evaluate the effect of different endodontic treatment options on stress distribution characteristics of hemisection of abutments. Methods: Three-dimensional (3D) FEA mathematical models were created to simulate a mandibular fi rst molar tooth with a removed distal root; 1: Endodontically treated remaining root, 2: Glass-fi ber-post restoration of remaining root, 3: polyethylene-fi ber-post resto-ration of remaining root, 4: zirconia-post restoration of remaining root. Vertical occlusal load (300N-at centric occlusion position) was applied on fi ve points at occlusal surface. Solidworks/Cosmoworks structural analysis programs were used for FEA. The stress distribu-tions and amounts were calculated according to the tensile stresses. Results: Highest root dentin tensile stresses were observed at end-odontically treated remaining root (275-300MPa). Maximum root den-tin stresses at other three treatments were similar (175-200MPa).



Also, the widespread of stress concentration areas differed accord-ing to various treatment confi gurations. Zirconia post application widened the stress concentration area at root structure. Glass-fi ber-post and polyethylene-fi ber-post models exhibited similar stress dis-tributions and values at remaining root structure. Conclusions: Leaving the remaining root with only a root fi lling at hemisection of molar tooth causes high tensile stresses at root den-tine structure. Stress distributions at remaining root of hemisection of molar tooth may be decreased by use of a post system that has a similar elastic modulus to dentin.


11.00 / 13.00

Chairperson: Giuseppe Cantatore

11.00 – 11.20

Correlation between gender and number of root canals in

maxillary and mandibular premolars. Clinical study.Marco Furri University of Selcuk, Faculty of Dentistry, Department of Endodontics, Konya, Turkey

Abstract

1184 maxillary (521 fi rst and 663 second) and 903 mandibular (332 fi rst and 571 second) premolars have been endodonically treated by the author between 1996 and 2010.Data regarding patient and teeth were collected by fi lling a form that will be introduced during the presentation.A chi-square analysis was performed to test whether a correlation existed between patient gender and number of root canals.Males had a statistically signifi cant higher number of root canals in maxillary second premolars (p<0,001) and mandibular fi rst premo-lars (p<0,001). Differences between fi rst maxillary and second man-dibular root canals were not statistically signifi cant.

11.20 – 11.40

Radicular resorption: classifi cation and therapiesCarlo Altamura, Giovanni SchianchiItaly

Abstract

Radicular resorption is an entity whose aetiology is still not clear and defi ned and it often puts us in front of diffi cult operative choices due to its unpredictable nature and typology. Root resorption is di-agnosed during routine radiographic controls or examinations and it always leads to careful choices, with regard to the future of the treated tooth. Among its causes we can list: A) Mechanics (root re-shape or fracture);B) Traumatic (accidental , occlusal); C) Pressure (orthodontic ,tu-moural ); D) Systemic (Paget Disease)E) Substitutive (reimplantations); F) Infectious (periodontal and end-odontic). All these causes trigger a cellular group (macrofages, osteoclasts) capable of causing the harmful effects that we fi nd during our clini-cal work. Starting with the diagnosis, the elective choice is to per-form the treatment as soon as possible, due to the danger for the compromised tooth , that in some cases can results in high degree of resorption or anchylosis. After the Classifi cation of the resorp-tions , supported by observation at the microscope , we will take into consideration, presenting cases movies , all the typologies of this disease and the consequent treatments that we have chosen: from apical resorption, to intra and extra radicular resorption. We will also discuss the most diffi cult situations we have met during our daily clinical work.

11.40 – 12.00

Management of crown-root and cervical root fractured

teeth: a follow-up case series Ceyhanli Kadir Tolga, MK Caliskan, U Tekin, YU Topçu, A Aladag Ege University School of Dentistry, Departments of Endodontics, Surgery, Orthodontics and prosthetic Dentistry, Izmir, Turkey

Abstract

We will present the long-term results of orthodontic or surgical extrusion of four maxillary incisors with complicated crown-root or cervical root fractures. Complicated crown-root or cervical root frac-tures are a relatively rare form of dental injuries, which occurs in 0.5-7 % of cases. Different treatment approaches are indicated for fractured teeth depending on the location of the fracture. The teeth with complicated crown-root fracture or cervical root fracture pres-ent problems for coronal restoration, especially when the fracture line extends below the marginal bone level. Orthodontic or surgical extrusions to save such teeth have been recommended. The aim to present these case series is to discuss the long-term results of orthodontic or surgical extrusions of four maxillary incisors with complicated crown-root or cervical root fractures of four patients, 16 to 48 years old. Endodontic treatments were performed with cal-cium hydroxide paste as the intracanal medication and the root ca-nals were obturated with resin sealer and gutta-percha using lateral condensation technique. After resolution of peria pical radiolucency, coronal restoration was placed using metal reinforced full porcelain crown following completion of fi ber post and composite core restora-tion for each case. Clinical and radiographic examinations (follow up period: 18 months to 4 years) revealed apical healing without root resorption and healthy supporting tissue. The results encouraged the use of both extrusion methods. How-ever orthodontic forces render a more biological way of extrusion and surgical extrusion is a one-step procedure which is simpler and less time-consuming than orthod ontic extrusion.

12.00 – 12.20

The open apex: how close to close?Abu Tahun IbrahimUniversity of Jordan

Abstract

Classic treatment options when treating the necrotic but immature permanent tooth, is a problem that often leads to resolution of apical periodontitis, with the tooth remaining susceptible to fracture as a result of interruption of apical and dentinal wall development. Many tissues, given the right condition are programmed for self-re-generation to restore the lost part.Regeneration of an injured or necrotic pulp would be the ideal heal-ing of a pulp wound and the best root fi lling possible. The tremendous increase in our clinical tools and knowledge dur-ing the last 15 years in addition to the numerous reports of case series conducted on human patients , should be refl ected in our clinical management to ideally design the future safe, effective, and consistent method for regenerating a functional pulp-dentin complex in our patients.

12.20 – 12.40

The use of MTA as an apical plug in immature or resected

teeth with periapical lesionsGozde Kandemir Demirci, Umit Günes Ozcan, Mehmet Kemal CaliskanTurkey

Abstract

Aim: To present two cases in which substantial healing occurred with the use of MTA to create an apical plug in the roots of immature or resected teeth.Method: In the fi rst appointments radiographic examinations indicat-






42

ed that both teeth with wide-open apex and periapical radiolucency. After evaluating all the diagnostic data, a root canal re-treatment of left maxillary central incisor and for other patient root canal treat-ment of immature left central incisor were planned. The root canals were prepared with H-fi les using 2,5 % NaOCl irrigation and calcium hydroxide were used as intracanal medicament .MTA was prepared according to the manufacturer’s instructions. An endodontic plugger adequate for the length of the canal was used, and the stopper was fi xed 1 mm behind the working length. MTA was inserted into the canal and pushed further in with a plugger. A radiograph was taken to ensure there was no excessive MTA.A cotton pellet moistened with distilled water was placed over the MTA, and the access cavity was sealed with a temporary fi lling. After 24 hours, the temporary fi ll-ing material and cotton pellet were removed. Then the MTA in the remaining pulp space was obturated with gutta-percha and resin sealer. Finally teeth were restorated with composite resin. Result: Clinical follow-up 14 months later revealed adequate clini-cal function, absence of clinical symptoms and no signs of periapical lesion.Conclusion: The positive clinical results of this cases are encourag-ing for the use of MTA as an apical plug in immature or resected teeth with periapical lesions.The results of treatments will be discussed along with literature.

12.40 – 13.00

R phase advantages in shaping the curve canalsPhilippe SleimanFrance

Abstract

In curved canals we have two kinds of clinical stress on the fi le; bend-ing stress, and torsional stress. Bending stress is when the fi le is passing inside a curve and is subjected to two stresses of an equal level. One is stretching on the outer part of the curve and the second is compression of the alloy structure from the internal part of the curve. This kind of stress cannot break a fi le, but it can lower its tor-sional stress at least by 30% from the fi rst few seconds that the fi le is active inside the curve. The second kind of stress the fi le is subjected to, torsional stress, is the most dangerous stress.Intensive research was conducted in order to change the crystalline structure and obtain a dual phase structure with it’s main character-istic. This is known as the “R phase.” or the pre-martensitic phase. This phase has the advantage of taking increased pressure while still increasing the torque value. This phase appears after the austenite phase and still increases in torque until the ultimate deformation point. During this phase we have actually two kinds of R phase; R1 and R2. According to thermal cycling tests under various constant stresses, the transformation strain of R 2 is greater than that of R 1. With increasingly applied constant stress, the latters strain increases and the former decreases. With this R phase shaping the curves will be much easier to perform and safer, since the fi les produced with this alloy are much fl exible than any other fi le with the same dimensions. As for the clinical applications, we must be alert in order not to put a very large fi le in the curve, like a taper .10 or a taper .08, but it will depend on the severity of the curves. There are two reasons for this:1- Avoiding a taper lock which can lead to a separation of the fi le in case the curve is severe, or we may damage our fi les.2- The fi les are aggressive and sometimes a strip perforation may occur.

13.00/14.30 LUNCH

14.30 / 16.30

Chairperson: Gianluca Plotino

14.30 – 14.50

The operative microscope: a comfortable and ergonomic approach to dental workMauro Rigolone Department of Endodontics, Prof. E. BeruttiUniversity of Turin Dental School, Turin, Italy

AbstractThe operative microscope was fi rst introduced into dental practice some years ago in the United States. Dental microscopy has, in recent years, led to greater precision in everyday practice, and to improved outcomes. The operative microscope provides different magnifi cation options, combined with coaxial illumination, which creates a shadow-free fi eld of vision. However, as this tool is increasingly employed in dentistry, most of the fundamental ergonomic rules dentists are fa-miliar with must be changed, so as to achieve a favourable viewpoint and a better approach to the operating fi eld.The position imposed by working with the operative microscope is often a forced one, entailing incorrect posture for both dentists and their assistants. The aim of this report is to suggest a comfortable and effi cient working position for microscope users, to prevent the common muscle and skeletal disorders that affect dentists and as-sistants world-wide. The study also assesses the ways in which den-tists’ posture and the placement of the working team may infl uence working procedures, with the goal of achieving better performance and increasing the success and quality of the work.

14.50 – 15.10

Deep carious lesions: when endodontic treatment is

necessary Nicola ScottiDDS, Assistant Professor, Department of Operative Dentistry, Prof. E. BeruttiUniversity of Turin Dental School, Turin, Italy

Abstract

The operative microscope was fi rst introduced into dental practice some years ago in the United States. Dental Cleansing of carious le-sion is a crucial step in the adhesive resin composite restorations. However, when cavities are close to the pulp chamber, endodontic treatment may be necessary. Few data are available about the con-sequences of adhesive procedures in deep cavities, or the outcome of pulp-capping procedures. This presentation reports a clinical trial assessing post-operative pain and clinical outcome after extensive adhesive restorations with two different adhesive systems: self-etch-ing and total-etching adhesives.Two-step self-etching adhesive systems are clinically indicated in hybridization of extremely deep cavities, because they appear to be less aggressive towards the pulp. However, the results of this in vivo study show that self-etching and total-etching adhesives are clini-cally comparable with regard to pain and post-operative sensitivity. Moreover, the one-year follow-up evidenced a better marginal seal in restorations performed with total-etching adhesive.

15.10 – 15.30

Response of human pulps capped with PDGF. Pilot study Gaia Pellegrini, C Dellavia, P Generali, C Allievi, D Re, G Rasperini Dept. of Human Morphology and Biomedical Sciences “Città Studi”, Milan, Italy. Private practiceDental Clinic, Dept. of Surgical, Reconstructive and Diagnostic Sciences University of Milan, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan, Italy.

Abstract

Introduction: Growth factors showed the potential to promote odon-toblast-like cells differentiation and induce the formation of repara-



tive dentine. Aim of this pilot study is to evaluate the pulp response after capping procedure performed with PDGF BB. METHODOLOGY. Two third molars (site A and site B) were treated. Class I cavities were prepared and the exposed pulps were capped with cotton pel-let embedded in PDGF solution and fi lled. Teeth were extracted after 40 days and processed for routine histological examination. The hard bridge formation and the infl ammatory pulp reaction were evaluated. RESULTS. In site A, incomplete and thick dentine bridge formation (mean thickness of 199.5um) was observed. The pulp tissue close to the remaining exposed pulp was moderately disorganized with many fi broblasts and few infl ammatory cells. In site B, incomplete dentin bridge (mean thickness of 215um) covered part of the defect. The pulp was overall normal but a limited area close to the dentin bridge interruption, where a clot-like tissue with many fi broblasts and few infl ammatory cells was observed. CONCLUSION. PDGF-BB does not elicit infl ammatory response neither induces the extensive matrix deposition and appears to be a safe pulp capping agent.

15.30 – 15.50

Current strategy in achieving success with endodontic

treatment T Tsurumachi, M Hayashi, B Ogiso Department of Endodontics, Division of Advanced Dental Treatment, Nihon University School of Dentistry, Tokyo, Japan

Abstract

Modern endodontic treatment has changed dramatically during the past few decades: the diagnostic accuracy of cone beam computerized tomography, ultrasonic irrigation, endodontic microscope examina-tion, root canal shaping with Nickel-Titanium instruments. The amaz-ing technical advance is clear, yet believes the greater importance of basic procedural factors in achieving predictable endodontic success. The major goals of endodontic treatment are to 1) remove the irritants from the root canal systems; 2) fi ll or obturate the cleaned and shaped system; 3) prevent future recontamination of sealed root canals. The long-lasting success of an endodontic treatment is not guaranteed by new endodontic materials or modern types of instruments, but by the practitioner’s ability to support the biological principles and useful-nesses, proven in long-term clinical studies. This presentation will describe the new diagnostic method and man-agement strategy based on the latest available information, and also show clinical cases.Acknowledgements This study was supported by the Sato fund in Ni-hon University School of Dentistry.

15.50 – 16.10

Pulse oximetry as a tool to assess pulp vitality in patients

submitted to radiotherapy T Simony Kataoka, E Gondim-Junior, FA Alves, OF Pessoa, G Gavini, CL Caldeira Department of Endodontics - University of São Paulo, São Paulo, BRSchool of Dental Medicine - University of Pennsylvania, Philadelphia, USDepartment of Oral Pathology - University of São Paulo, São Paulo, BRDepartment of Endodontics - Universitary Center of Pará, Belém, BR

Abstract

To evaluate pulp oxygenation level (%SpO2) in patients with malignant intraoral and oropharyngeal tumors treated by radiotherapy (RT). 20 patients were selected and two teeth of each of them (n=40) were analyzed by pulse oximetry at times: I- before RT; II- at the beginning of RT (30Gy-35Gy); III- at the end of RT (60Gy-70Gy) and IV- after 4-5 months of the beginning of the RT. Mean %SpO2 was 93%, 83%, 77% and 85%, respectively. Student’s t test (p<0.01) showed statistically signifi cant differences between Time I and the other three times. Time III was different when compared to Time II, and there was no difference between Times II and IV. Pulp tissue had lower %SpO2 at the end of RT and, as values obtained in Time IV were close to those of Time II, pulp tissue may show normal blood fl ow after radiation therapy.






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NOTES

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