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Official Publication of IDA Karnataka State BranchOfficial Publication of IDA Karnataka State BranchKSD

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ISSN : 09733442

Issue 1

Volume 37

Jan. - March 2020

Dearcolleagues,

EDITORIAL

Editorial Advisory Board

1

Greetings from the editorial board of IDA Karnataka State Dental Journal.

In the current scenario of widespread challenges and inequitable competition in every profession, dentistry is no different. The very existence of dentists depends upon being the best in a lot rather than good. The need to keep oneself updated with the latest trends and technology is also an emerging demand, especially while dealing with patients who seek treatment after doing an online study on dentistry.

The latest research protocols and studies undertaken by the young, emerging dentists and the established senior professionals are an integral part of the �ield. This journal has been carefully kneaded to keep up with the upcoming trends in dental profession.

IDA Karnataka State Dental Journal is indebted to all its readers, sponsors and contributors. Dr. Supriya Manvi, Ph.no. 9448145452, email :[email protected], Professor and Head of the Department, Department of Implantology, KLESIDS. (Assistant Editor, IDA Karnataka)

Dr.B.K.SrivastavaProfessor and Head of the Department,

K.L.E Society's Institute of Dental Sciences, Bengaluru.

(Editor In-Chief, IDA Karnataka State Branch)

INSTITUTIONNAME DEPT EMAILIDPH.NO.

[email protected]. Neetha Harisha Oral medicine CODS, Davangere

Dr. Vivek H P Community Dentistry CODS, Davangere 8095306448 [email protected]

Dr. Mahesh Chandra Community Dentistry Maruthi dental college [email protected]

Dr. Prashanth Conservative Dentistry BIDAR 8861449056

Dr. Prashanth B R

Dr. Praveen B

Dr. Vinod

Dr. Sudarshan

Dr. Sathyadeep

Dr. Ramesh

Dr. Babitha

Dr. Jayprakash

Dr. Madhu

Dr. Mallikarjuna K

Conservative Dentistry KLEIDS 9449638113 [email protected]

CODS, Davangere 9986393343

Oral Surgery Dayanand Sagar 9845190783

KLEIDSOral Surgery

Orthodontics Dayanand Sagar 9980142380

Orthodontics Sharavathi dental college, Shimoga

9632522799

Periodontics 9448966166

Periodontics Coorg Institute of Dental Sciences

9972912662

Pedodontics KLEIDS 9535152325

Pedodontics CODS, Davangere 9448040502 [email protected]

Prosthodontics

9845571071

9449104316

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected]

[email protected], Davangere

[email protected]

[email protected]

PRESIDENT MESSAGE

SECRETARY MESSAGE

I am greatful for the opportunity given to me to bring the activities of the Karnataka Branch to its fullest extent.

Dental care being a prerequisite to a healthy life, more stress would be laid on dental health awareness programmes, oral malignanly awareness camps, educating children on dental health and many more to come.

Also interaction between each branches would promote advancemend dentistry thro exchange of ideas both at National and international platform.

This would help the upcomming experts further improve in complehensivehealth care.

Looking forward for an happening year ahead.

From the Office of IDA Karnataka state branch,

Gree�ngs to all the members of IDA Karnataka state branch. The New office bearers took over in the month of December 2018 to manage the office for the nest 04 years. The good work done by previous office bearers have taken some significant decision that will benefit the members. Our task will be to effec�vely implement the programs. The new office bears along with the President wish the Editor in chief and the editorial team of KSDJ all the very best to bring out the journal for the next 04 years.

The local branches have done a wonderful job �ll date. We are thankful for all the hard work, Devo�on and �me spared by the members.

Dr.Shivaprasad.SHon. State Secretary,

IDA Karnataka State Branch

2

Dr.SudhindraKumarN.NHon. President

IDA Karnataka State Branch

IDA KARNATAKA STATE BRANCHLIST OF OFFICE BEARERS FOR THE YEAR 2018-19

3

OFFICE BEARERS : 2019-2020

INDIAN DENTAL ASSOCIATION KARNATAKA STATE BRANCH

KARNATAKA STATE BRANCH

Dr. Sudhindra Kumar N.N

Dr. Shivaprasad S

Dr. Tilakraj T.N

Dr. Mahesh Chandra

Dr. Narendra Kumar M

Dr. Ramamurthy T. K

Dr. Mahendra Pimpale

Dr. V. Ranganath

Dr. Sanjay Kumar D

Dr. Adarsh C

Dr. Annaji A.G

Dr. Shivasharan Shetty

Dr. Ramachandra Mallan

Dr. Raghavendra Pidamele

Dr. Srinidhi D

Dr. Sanjay Mohan Chandra

Dr. Charan Kumar Shetty

Dr. S.C. Veerendra

Dr. Sushanth V.H

Dr. Nandlal B

Central Council Members

Dr. Keerthi Shetty

Dr. Mahesh K.P

Dr. Sudarshan Kumar R.N

Dr. Nanda Kishore B

Dr. Chetan R

Dr. M.C. Shashikant

Dr. S. Ashwath Raju

Dr. Kiran Raddar

Dr. Bharath S.V.

Dr. Veerendra Kumar B

Dr. Sheshadri R

Dr. Sachin S

Dr. Raghavendra Katti

Dr. Krupashankar R

Dr. Chaitanya Babu

Dr. Prabhuji M.L.V.

Dr. Jagadeesh. C

Dr. Deepak J.R.

Dr. Girish Katti

Dr. Prathap Kumar Shetty

Dr. Sanath Shetty

Dr. Prashanth G M

Dr. Roshan Shetty

Dr. Shuban Alva

Dr. Padmaj Hegde

Dr. Smitha T

Dr. Uma R

Dr. Manjunath R K

Dr. Syed Mohammed Faiz

Dr. Manjunath Mesta

Executive Committee Members

Dr. Shivasharan Shetty Dr. Ranganath V Dr. Madhusudhan Reddy Dr. Raghunath N

Vice Presidents

PresidentDr. Sudhindra Kumar [email protected]

Mob: 9242146403

Hon. TreasurerDr. Sushanth V.H

[email protected]: 9986914030

CDE ChairmanDr. Ravi M.G.


CDH ChairmanDr. Manoj Maxim D’lima


Joint SecretaryDr. Mohan Kumar K.P


Assistant Secretary Dr. Praveen S. Basandi


Immd. Past PresidentDr. H.P. Prakash

President Elect Dr. Srinidhi D

Editor in Chief Dr. B.K Srivastava


Hon. SecretaryDr. Shivaprasad S


CONTENTS

1. DentinHypersensitivityAReview 05-09 -Dr.Nischith.K.G.,Dr.Srikumar.G.P.V.

2. LoadingProtocolsForImplants 10-14 -Dr.KesavaReddy.K,Dr.RenukaPrasanna.G.S

3. RecentConceptsInUseOfIntracanalMedicaments 15-18 -Dr.L.KrishnaPrasada

4. Digitalimpressions,notascience�ictionanymore! 19-23 -Dr.M.SunithaRoy.,Dr.Soudhamini.V.Rao,Dr.LakshmipathiReddy.P

5. HidroticEctodermaldysplasia 24-26 -Dr.Sujata.M.Byahatti

6. LightWeightMaxillaryCompleteDenture: ACaseReportOfASimpli�iedTechniqueWithThermocole 27-30 -Dr.SivaranjaniGali,Dr.VibhaShetty,Dr.SmithaRavindran

7. Anevaluationoftheeffectivenessofvariousdisinfectantsonthe microorganismspresentinDentalrubberbowls 31-35 - Dr.Rajeswari.C.L.,Dr.Srivatsa.G.

8. AcrylicRemovablePartialDentures-MinimizingDamageToTheTissues 36-39 -Dr.Srivatsa.G,Dr.RohitShetty

9. StudyontheusefulnessofOrthopantomograph forearlydiagnosisofosteoporosis 40-45 -Dr.ShobhaB.Sikkerimath,Dr. Ramesh

10 GuidingMandibleBackHome:Prosthetic Rehabilitation:CaseReport 46-50 -Dr.AjayGDoni,Dr.SupriyaManvi,Dr.RajeswariC.L,Dr.RohitMohanShetty, Dr.SrivatsaG,Dr.DeeptiKumar

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Abstract

Dentin hypersensitivity is a common condition of transient tooth pain associated with a variety of exogenous stimuli.

There is substantial variation in the response to such stimuli from one person to another, Except for sensitivity

associated with tooth bleaching or other tooth pathology, the clinical cause of dentin hypersensitivity is exposed

dentinal tubules as a result of gingival recession and subsequent loss of cementum on root surfaces. The most widely

accepted theory of how the pain occurs is Brännström's hydrodynamic theory of dentin hypersensitivity.

Keywords:Dentin hypersensitivity, Brännström's theory, dentinal tubules.

IntroductionDentin hypersensitivity is a common condition of transient tooth pain caused by a variety of exogenous stimuli. The exogenous stimuli include thermal (cold), tactile (touch), or osmotic changes (sweets or drying the

1,2surface).

Hypersensitivity means painful response to stimuli not normally associated with pain. The response to a stimulus varies from person to person due to differences in pain tolerance, environmental factors,

3and emotional state.

Etiology&MechanismOfDentinHypersensitivity:The most common clinical cause for exposed dentinal tubules is gingival recession. The recession may or may not be associated with bone loss. If bone loss occurs,

4then more dentinal tubules can be exposed.

When gingival recession occurs, cementum is exposed. Cementum, being a very thin outer protective layer on dentin, is easily abraded or eroded away. This leaves the underlying dentin, which consists of tubules which contain the protoplasmic projections of the cells (odontoblasts) within the tooth pulp chamber. These cells contain nerve endings and when disturbed,

5,6depolarize. This neural discharge is interpreted as pain. The pain has a rapid onset and is usually of short

2duration, but it can persist as a dull ache.

As noted earlier, the most accepted theory of how the

5

Authors:Dr.Nischith.K.G.¹,Dr.Srikumar.G.P.V.²

DentinHypersensitivityAReview

1. Dr.NISCHITH.K.G. MDS, Prof & HOD Dept Of Conservative Dentistry & Endodontics. Purvanchal Institute Of Dental Sciences. Gorakhpur. (U.P)

2. Dr.SRIKUMAR.G.P.V. MDS, Assistant Prof. Dept Of Conservative Dentistry & Endodontics. Purvanchal Institute Of Dental Sciences. Gorakhpur. (U.P)

pain occurs is Brännström's hydrodynamic theory of 7,8dentin hypersensitivity. This postulates that �luids

within the tubules are disturbed either by temperature changes or physical osmotic changes and that these �luid changes stimulate a baroreceptors which leads to neural discharge (depolarization).

Once the dentinal tubules are exposed, there are often oral processes or habits that keep them exposed. These include poor plaque control, enamel wear, cervical erosion, incorrect oral hygiene technique, and exposure to acids.

Since dentinal tubules naturally sclerose and plug themselves up in the oral environment over time, treatment should focus on eliminating factors associated with continued dentinal tubule exposure.

CommoncausesofGingivalRecession:

1. Inadequate attached gingiva2. Prominent roots3. Toothbrush abrasion4. Pocket reduction periodontal surgery5. Oral habits resulting in gingival laceration, i.e., traumatic tooth picking eating hard foods6. Excessive tooth cleaning7. Excessive �lossing8. Gingival loss secondary to speci�ic diseases, i.e., NUG, periodontitis, herpetic gingivostomatitis

KSDJ / Vol 36/Issue 3/August - December 2019

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TreatmentStrategies:Treatment of dentin hypersensitivity is challenging for both the patient and Dentist for two reasons. It is dif�icult measuring/comparing different patient's pain and it is dif�icult for patients to change the habits that initially caused the problem. Hypersensitivity can resolve without treatment or may require several weeks of desensitizing agents before improvement is

9seen.

Therearetwoprincipaltreatmentoptions:Ÿ Plug the dentinal tubules preventing �luid �low, orŸ Desensitize the nerve, making it less responsive to

stimulation

All of the current treatment modalities addressthesetwooptions:No single agent or form of treatment has been found effective for all patients. Solutions, gels and pastes-containing �luorides in varying compounds and percentages, calcium hydroxide, strontium chloride, potassium nitrate, sodium citrate, formaldehyde, or potassium or ferric oxalate have all been tried, with

2varying degrees of success.

ReasonsforContinuedDentinalTubularExposure:1. Poor plaque control, i.e., acidic bacterial by products2. Excess oral acids, i.e., sodas, fruit juice, swimming pool chlorine, bulimia3. Cervical decay4. Toothbrush abrasion5. Tartar control toothpaste

NerveDesensitization:Currently there is only one compound that claims to desensitize the nerve. That compound is potassium nitrate. It is theorized that potassium nitrate penetrates through the dentinal tubules to the nerve.

The potassium ion may depolarize the nerve and prevent it from repolarizing, thereby, preventing it from sending pain signals to the brain It is possible in the future that desensitizing toothpaste may contain two active ingredients.

One would be designed to penetrate the tubule and desensitize the nerve and the other to occlude the

10tubules.

Prior to the development of potassium nitrate as an desensitizer, Occluding or sclerosing the open dentinal tubules was the primary method used to control hypersensitivity. Now that approach, along with covering the exposed dentinal tubules, is primarily reserved as a professional treatment method.

Methods to physically cover the dentinal tubules include periodontal surgery to bring the tissue over the surface of the exposed dentinal tubules or placing a dental restoration over them, protecting the tubules from the oral environment.

The other means of covering the dentinal tubules is to seal the surface either with a dentinal sealer or a composite/glass ionomer restoration.

The alternative approach to block the tubules is to occlude/sclerose inside of the dentinal tubules. Tubule occlusion can occur either naturally over time or through professional intervention.

Minimizing or eliminating hypersensitivity is to sclerose the dentinal tubules from within. Older patients tend to have less sensitivity because the tubules are naturally sclerosed with secondary dentin.

Professional (by prescription or of�ice applied) dental products, which occlude the dentinal tubules, comprise the vast majority of products available to control hypersensitivity. One subgroup of these products are those which contain ions or salts which are hypothesized to precipitate within the tubule.

This includes the stannous ion in stannous �luoride, Clinical studies have documented reduction in dentinal hypersensitivity using a solution that contained stannous, sodium, and hydrogen �luoride. Symptoms

11,12were lessened with regular usage.

The stannous ions may precipitate together into a large enough mass to occlude dentinal tubules. Oxalate is another ion used in professionally applied desensitizing solutions. The oxalate ions react with the calcium in the tooth to form insoluble calcium oxalate crystals that

13,14occlude the tubules.

Other products designed to occlude the tubules are those such as Gluma which contains glutaraldehyde


7

which is hypothesized to precipitate and coagulate proteins/amino acids within the tubule. Gluma also

14contains a methyl methacrylate to seal the tubules.

Dentin bonding agents containing methyl methacrylate or some type of surface precipitant can be used. The recommended chairside treatment of dentinal sensitivity are :

All Bond Desensitizer, Micro prime. However, there are currently no clinical studies published that support in vivo experience for these products.

TreatmentofDentinHypersensitivity: Treatment Options:1. Desensitize the nerve a. potassium nitrate

2. Cover the dentinal tubules: a. periodontal surgery/grafting b. composite/glass ionomer restoration c. crown placement d. plug (sclerose) the dentinal tubules.

1. ions/salts a. stannous �luoride b. sodium �luoride/stannous �luoride combination c. potassium oxalate d. ferrous oxide e. strontium chloride f. in combination with an adhesive.

2. precipitates - proteins/amino acids a. glutaraldehyde.

3. resins a. dentin sealers.

When a patient presents with sensitive dentin, the initial diagnosis should eliminate any possible reasons such as decay, cracked tooth, or irreversible pulpitis that may mimic dentin hypersensitivity.

Once the problem has been identi�ied as dentin hypersensitivity, identify the reason for the exposed d e n t i n a l t u b u l e s a n d e t i o l o g y c a u s i n g t h e hypersensitivity should be eliminated.

If the hypersensitivity persists even after the etiology is

removed, then the simplest and most cost effective approach is desensitizing toothpaste, which is used to brush the teeth twice a day for at least two weeks.

Depending on the patient's response to the treatment and depending on the etiology and severity of the problem, the next step would be to apply dentin bonding agent to the surface or restore the affected teeth with composite restorations covering the exposed dentinal tubules.

When the pat ient � irst presents with dent in hypersensitivity, they should be informed of the series of steps that may be necessary to eliminate the problem.

Also, when fully informed, the patient is put in charge of the decision making process. In rare cases no matter what treatment procedure is tried, the hypersensitivity

14may still persist.

The patient should also be informed at the beginning, that the ultimate way of desensitizing a tooth, is extirpation of the Dental pulp; Endodontic treatment.

This will clearly desensitize the tooth, but requires additional restoration for its �inal treatment. If the patient is informed about this �inal solution in the beginning, then they have the full treatment plan and fully understand their and your choices relative to this annoying problem.

Dental bleaching has been reported to cause a number of side effects, including tooth sensitivity, gingival irritation, tooth pain, tingling of the tissues.

The hypersensitivity that occurs in association with bleaching has been attributed to patient factors, length of exposure to the bleaching agent, the concentration of the bleaching agent, pH of the whitening solution.

Patients, especially those who already have exposed dentin or already have some type of hypersensitivity or those with larger pulps, should be warned that they may have a greater risk of hypersensitivity secondary to bleaching.

If a patient has sensitivity secondary to bleach use, they should be instructed to reduce the frequency or duration or discontinue the bleaching process, depending on the severity of the sensitivity reaction.

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Another option is to recommend a bleach product that contains potassium nitrate, or recommend the patient desensitize their teeth with a potassium nitrate containing toothpaste for several days prior to using the bleach. This could entail using bleaching trays to hold the potassium nitrate containing toothpaste in place around the teeth. This would desensitize the nerves and allow the patient to use the bleach.

The higher the concentration of bleach, the greater the risk of sensitivity. 10% Carbamide peroxide causes less sensitivity, but the bleaching process is slow, though it will eventually get to the same level of whiteness as the

15higher concentrations. 20% Carbamide peroxide accelerates the bleaching process, but sensitivity may be intolerable.

ConclusionDentin hypersensitivity is a problem that plagues many patients. The initial or continued clinical cause, in the majority of situations, is gingival recession. Recession exposes root surfaces and once the thin cemental layer is removed, the dentinal tubules are exposed.

The initial treatment choices to treat dentin hypersensitivity are to cover up or occlude the tubules or to desensitize the nerves so they are not as responsive to stimulation. The only product available to desensitize the nerve is potassium nitrate.

This compound is the active ingredient in all desensitizing toothpastes.

Occluding or covering up the tubules can be accomplished using many products. Some of these seal the outer edge of the tubules and others precipitate salts or proteins within the tubules. The end result is the tubules are blocked; preventing �luid movement within them.

Patients should be informed of all the possible steps that may be necessary to eliminate their hypersensitivity.

The �irst step should be to identify and eliminate the cause.

The next is to rectify the recession or seal the exposed dentinal tubules from the oral environment. If the patient is thoroughly informed of all the possible steps then they become a partner in the treatment process.

References

1. Kanapka JA. Current treatment for dentinal hypersensitivity. A new agent. Compend Contin Educ Dent 1982;(Suppl 3 ):S118-20.

2. Addy M, Mostafa P, Newcombe RG. Effect of plaque of �ive toothpastes used in the treatment of dentin hypersensitivity. Clin Prev Dent 1990;12: 28-33.

3. Orchardson R, Collins WJ. Clinical features of hypersensitive teeth. Br Dent J 1987;162: 253-6.

4. Bal J, Kundalgurki S. Anbsp;Tooth sensitivity prevention and treatment. A reviewOral Health 1999;89:33-4, 37-8, 41.

5. Brannstrom M, Astrom A. The hydrodynamics of the dentine; its possible relationship to dentinal pain. Int Dent J 1972;22: 219-27.

6. B e r m a n L H . D e n t i n a l s e n s a t i o n a n d hypersensitivity. A review of mechanisms and treatment alternatives. J Periodontol 1985;56: 216-22.

7. Brannstrom M. The hydrodynamic theory of dentinal pain: sensation in preparations, caries, and the dentinal crack syndrome. J Endod 1986;12: 453.

8. Brannstrom M, Johnson G, Nordenvall KJ . Transmission and control of dentinal pain: resin impregnation for the desensitization of dentin. J Am Dent Assoc 1979;99: 612-8.

9. Carranza FA, Newman MG. Clinical Periodontology, ed. 8, Philadelphia, 1996, W.B. Saunders Company.

10. American Dental Association Council on Scienti�ic Affairs: Acceptance Program Guidelines Products for the Treatment of Dentinal Hypersensitivity, May 1998.

11. Thrash WJ, Jones DL, Dodds WJ. Effect of a �luoride solution on dentinal hypersensitivity. Am J .Dent 1992;5: 299-302.

12. Blong MA, Volding B, Thrash WJ, Jones DL. Effects of a gel containing 0.4 percent stannous �luoride on dentinal hypersensitivity. Dent Hyg (Chic) 1985;59: 489-92.

13. G re e n h i l l J D, Pa s h l ey D H . T h e e ff e c t s o f desensitizing agents on the hydraulic conductance of human dentin in vitro. J Dent Res 1981;60: 686-98.

14. Wichgers TG, Emert RL. Dentin hypersensitivity. A review. Gen Dent 1996;44: 225-30.

15. Mokhlis GR, Matis BA, Cochran MA, Eckert GJ. A clinical evaluation of carbamide peroxide and hydrogen peroxide whitening agents during daytime use. J Am Dent Assoc 2000;131: 1269-77.


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CorrespondenceAddress: Dr.NISCHITH.K.G. MDS, Prof & HOD Dept Of Conservative Dentistry & Endodontics. Purvanchal Institute Of Dental Sciences. Gorakhpur. (U.P)


Abstract

The dramatic change in which we practice dentistry today was brought about by the coincidental discovery of

osseointegration by Branemark and his coworkers. One of the prerequisites for establishing osseointegration as

advised by Branemark is a stress free healing period of 3-6 months. The rationale of delayed loading was that the

premature loading could result in �ibrous encapsulation rather than bone integration.

Success with Bran mark's protocol has a deterring factor in the form of extended treatment period which sometimes

precludes the patient from opting to implant therapy. Increasing functional and aesthetic challenges, modi�ications of

implant shape and surface characteristics have prompted implantologists to reduce the treatment period by loading

the implant immediately at the time of placement. The immediate loading of dental implants clearly represents the

change but also warrants discussion.

INDEXWORDS:osseointegration, immediate loading, delayed loading ..

IntroductionThe predictability of implant integration according to Branemark et al was obtained by adherence to a strict surgical and prosthodontic protocol. During the course of their clinical trial various delayed loading periods were tried and they asserted that osseointegration required a long healing period of at least 3 months in the mandible and at least 5-6 months in the maxilla.Factors that led Branemark to conclude that “a minimum healing period of 3 months is required, otherwise the risk of immediate or late implant mobility greatly increases” are due to:

Patient Selection with Poor Quality and Quantity Bone Non-Optimized Implant DesignShort ImplantsNon-Optimized Surgical PlacementNon-Optimized Surgical TechniqueBiomechanically Demanding Prosthesis

It is thus legitimate to question if this extrapolation applies to more standard conditions, involving recipient sites with better bone quality and quantity, rede�ined surgical and prosthetic protocols and different implant designs.

Authors:Dr.KesavaReddy.K¹,Dr.RenukaPrasanna.G.S²

LoadingProtocolsForImplants

1. Dr.KesavaReddy.K Assistant Professor, Dept of Prosthodontics, College of Dental Sciences, Pavilion Road, Davangere, 577004 Karnataka, India

.2. Dr.RenukaPrasanna.G.S Assistant Professor, Dept of Prosthodontics, Sri Hasanamba Dental College and Hospital, Vidyanagar, Hassan, 573201 Karnataka, India.

Evolut ion Of Concept Of Implant Loading1Branemark'sProtocol :

The traditional Branemark protocol involves mainly 2 stagesa) Stage I : Fixture installationb) Stage II : Abutment Connection

The time lag between Stages I & II is 3-6 months depending on bone density.

Advantages:I) Minimal risk of infectionII) Prevention of apical growth of mucosal epitheliumIII) Reduced risk of undue early loading

EarlyLoading/ImmediateLoadingOften presented as immediate loading, in reality, according to this technique, the �inal prosthesis is �itted from 3 days up to 6 weeks post surgery.

1ProtocolForImmediateLoadingOfImplants :· Dense cortical bone: Class I, II or III bone (Lekhom &

Zarb classi�ication) dense bone is contributory to increased Implant-

bone contact and thus Primary stability.

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Ÿ Threaded implants: threaded implants have a greater functional surface area in contact with bone thereby effecting a better stress distribution at the implant bone interface.

Ÿ Use of 4 implants with adequate length and diameter, connected with a U shaped bar: for splinting and distribution of forces, reduces risk of macro and micro movement, minimizes rotational movements.

Ÿ Implants should be at least 10mm long This has been concluded as a minimum length of the

implant required to impart adequate primary stability in the presence of other factors.

Ÿ Bicortical engagement to be achieved whenever possible.

Ÿ As bone density is a prime requirement for stability, Bicortical anchorage affords Primary Implant Stability and micro motion.

Ÿ Meticulous Surgical Protocol with minimal trauma Excessive heat and/or trauma during surgery can

damage bone and result in bone resorption in the initial postoperative period.

Ÿ A screw-retained provisional restoration should be used where possible. Removal of the cemented restoration may result in micro motion at the interface, impairing osseointegration.

Ÿ The widest possible anteroposterior distribution of implants, this result in an effective stress distribution.

Ÿ Cantilevers should be avoided in the provisional restorations.

Cantilevers increase the load on the distal implants and thus deter osseointegration.

Ÿ Restrict immediate loading to mandible, in the interforaminal region. Avoid posterior mandible where forces are high.

Ÿ Use of rough surfaced (coating) implants, rather than smooth surfaced ones. This increases the surface area for osseointegration.

Ÿ Avoid tapping Ÿ Favorable Occlusal Scheme: Use of 30 degree teeth

and lingualised occlusion. Decreasing cusp inclines, modifying occlusal anatomy to include 1.5mm fossae instead of occlusal grooves. Opposing cusps should be narrowed. All these factors reduce the stresses on the implants and aid osseous integration.

Ÿ Whole Surface of Implant should be covered with bone in cases of peri-implant fenestration or dehiscence.

Ÿ While Bruxism and Smoking are deterring factors to osseointegration, they are not completely contra-

indicated for immediate loading but should be treated with caution

Ÿ Soft diet

2 ProgressiveBoneLoading:Roberts and Misch proposed progressive loading protocol based on the idea that gradual loading or stimulation will allow bone to mature, grow denser and improve in quality. Greater density equates to greater strength and thus the ability to tolerate greater forces and permit successful implant prosthetic treatment.

Indications- Less number of implants. - Softer the bone type - Cantilever prostheses- Patient force factor's As a general rule higher the risk factor's the more progressive loading is recommended.

Ø ElementsofProgressiveboneloadingprotocol:Ÿ Timeinterval:Two surgical appointments are used

for initial implant placement and stage II uncovery, separated by 3 – 8 month depending on bone density. F i v e p r o s t h e t i c s t e p s a r e s u g g e s t e d f o r reconstruction of partial / completely edentulous patients with each prosthetic step separated by a period of time, depending on bone density at the time of initial stage of surgery.

Ÿ Diet: Diet of the patient should be controlled to prevent overloading during early phases of restorative procedure.

During initial healing phase: avoid chewing in that area. From delivery of initial Transitional prostheses to delivery of �inal prostheses: Soft foods such as pasta and �ish.

After initial delivery of �inal prostheses: May include meat

After �inal evaluation appointment: Raw vegetables

After evaluation of �inal prosthesis for function, occlusion, proper cementation: Normal Diet · Occlusalmaterials:- During initial step --> no Occlusal material - At subsequent steps --> acrylic – decrease impact

force, compare to metal / porcelain.


11

- Final prostheses --> metal or porcelain. - If parafunction and cantilever length --> extend the

acrylic and soft diet for several months.

· Occlusalcontacts:The dentist gradually intensi�ies the occlusal contacts during prosthesis fabrication.

- During initial healing --> no occlusal contacts. - First transition prosthesis --> out of occlusion. - Cantilevers --> no occlusal contact. - Final restoration --> implant protected occlusion.

· Prostheticdesign:- First transitional acrylic restoration: patient has no

occlusal contacts and no cantilever. Its purpose is to splint the implants together and decrease stress, to sustain them to masticatory forces solely from chewing.

- Second transitional acrylic restoration – Occlusal contacts are placed on implants with Occlusal table similar to �inal restoration, but with no cantilever in non esthetic regions.

· Final restoration: Narrow Occlusal table and cantilever are designed with occlusal contacts following implant protected occlusion guide lines.

3NonSubmergedSingleStageProcedure:Several authors have shown that implants can osseointegrate even if placed above the soft tissue at the time of surgery. When applying the one stage surgical protocol, it is possible to use either the common implant pillar or the conical one. This latter implant is designed with a 3.5 mm conical part coronal to the threads, thus when the implant threads are anchored into bone, conical part will be mucosa piercing, the implant serves as a one piece implant pillar.

Advantages of Non Submerged Implants over Submerged Implants.1. One stage surgical procedure Less chair time Less pain Shorter healing period Reduction of related treatment cost

2. No micro gap at alveolar crest bone level Less crestal bone resorption, during healing and following initiation of functional loading More favorable crown-implant length ratio

3. Implant shoulder at soft tissue level Implant easily accessible for prosthetic procedures Excellent basis for cemented restorations

4,5,6,7ImmediateFunctionalLoading:The Provisional restoration delivered is in full occlusal contact with the opposing dentition. In case of removable prostheses, the protocol essentially involves p l a c e m e n t o f 4 i m p l a n t s i n t h e m a n d i b u l a r interforaminal region, each of at least 10 mm length to achieve bicortical anchorage and splinted to each other by a U shaped bar.

For �ixed prostheses, the technique involves a few �ixtures that are allowed to heal by submerge Bran mark's protocol (Primary Implants) while a few are used to support the �ixed provisional prosthesis (Secondary Implants)

Secondary Implants are considered “disposable �ixtures” i.e. they are supposed to support the temporary prosthesis until the primary implants have gone through the healing stage successfully. If the excessive loading subjected to these implants, during the healing phase, impairs, osseointegration, they are eliminated. If not an assessment is made regarding their inclusion in the �inal prosthesis.

7ImmediateNon-functionalLoading:The provisional prostheses are not in occlusion and therefore serve only aesthetic purpose. This idea can be used when all centric and lateral occlusal contacts are with remaining natural teeth or with well integrated and healed implants. As compared with immediate functional loading, this method has the advantages of reducing the risk of biomechanical functional overloading (from parafunction). Even if the patient chews on the provisional prosthesis (while nevertheless encouraged to follow a soft food diet and avoid implant sites as far as possible the forces generated during chewing are less than 30 lbs/sq. inch and for less than 30 minutes a day. In case of parafunction, as much as 900 lbs/sq inch force is generated for many hours, day and night. This technique is especially useful in the anterior region.

FutureEvolutions8TeethInADayProtocol(“expeditedpatientcare”):

The protocol is based on the successful research for immediate loading of Branemark implants. A case report


12

was presented to explain the expedited patient care protocol / teeth in a day protocol for immediate loading of implants allowing patient to receive a �ixed implant supported prosthesis in a matter of hours. Indications for this type of protocol are patients who have enough quantity and quality of alveolar bone to ensure initial stability. They must also be compliant in following all post surgical instructions and limit the functional forces during the healing period for osseointegration by maintaining a soft diet for at least the �irst 2 months after the surgery.

Some precautions in case selection include patients with severe parafunctional habits. Patients with bone quality that does not allow for primary implant stability and non compliant patients who do not follow the post operative instructions of maintaining a soft diet during the primary healing period.

8,9BranemarkNovumprotocol:It can be used to treat periodontally hopeless or edentulous mandibles however the mandible must have an appropriate shape and approximately 12-13mm in height and 6-7 mm in width.

The system uses a series of 4 drill templates and light drill guides to precisely position 3 implants that are completely level and parallel to one another. Prior to surgery the clinician makes an impression of the maxillary teeth / denture, mounts the model using a face bow and selects the mandibular teeth. Immediately prior to surgery the vertical dimension of occlusion is recorded.

During surgery if teeth are present they are extracted, ridge is �lattened to 6-7 mm wide and using the guidetemplate(1) and round bur penetrations are made for implant positions one in center and one each on two posterior. The evaluationtemplate(2) is used to check for �latness of ridge and parallelism to maxillary occlusal plane. The positioningtemplate(3) properly places the central implant in a vertical direction with the proper buccolingual position. The implant is placed with a Novum implant mount; each diameter of implant has appropriate implant mounts. The implant is delivered until it bottoms out and is hand tightened with a wrench. At this point the positioning template is removed and the implant is evaluated. The Vtemplate(4) is attached loosely to central implant with a temporary screw and the 2mm drill guide is placed

laterally in the posterior sites. At this point the V template is totally sable and attached to the central implant and the two stabilizing screws. The posterior sites are now drilled following the same procedure.

A prefabricated lower bar is attached to implants. Similarly a prefabricated upper bar which precisely attaches to the lower bar are placed and bite registration is made at previously established VDO. The teeth are arranged, waxed up, tried in the same day and the prosthesis is delivered after processing.

8NordicBridgeConcept:It is a one stage surgical protocol in combination with early functional loading using conical / one piece implant (it has a 3.5mm conical part coronal to the threads). The implant threads are anchored into the bone, conical part will be mucosa piercing. The total treatment time from implant placement to delivery of the permanent FPD amounts to 5-7 days.

ConclusionThe level of predictability and high success of current implant therapy has provided reasons for reassessing long adopted surgical and prosthetic guidelines. With the trend of shortening treatment time and reducing patient discomfort, immediate loading has emerged as an alternate approach. Well controlled experimental and clinical studies have clearly demonstrated that the one stage surgical procedure is also applicable for the original 2 stage Branemark system. Therefore it is very much essential to know the requirements and bone responses to occlusal loading in the healing period. However it is important to note that meticulous case selection and also modi�ications in treatment plan is needed to integrate this treatment into daily practice. Studies are needed to understand the possibility of immediate loading in patients who are diabetics, osteoporotics, and smokers and in patients with systemic compromising diseases.

References1) Srinivasan B, Chitnis DP, Meshram SM. To Load

(Immediately) or not to Load – That is the Question ! JIPS 2003;3:31-38.

st2) Carl E. Misch:Dental Implant Prosthetics- I edn,PP 511-30.

3) Becker W, Becker BE, Israelson H, Lucchini JP, Handelsman M, Ammons W, Rosenberg E et al. One-step surgical placement of branemark


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implants : A Prospective multicenter clinical s t u d y. I n t J O r a l M a x i l l o f a c I m p l a n t s 1997;12:454-462.

4) Ericsson I, Nilson H, Lindh T, Nilner K, Randow K. Immediate functional loading of Branemark single tooth implants. Clin Oral Impl Res 2000;11:26-33.

5) Wol�inger GJ, Balshi TJ, Rangert B. Immediate Functional Loading of Branemark System Implants in Edentulous Mandibles : Clinical Report of the Results of Developmental and Simpli�ied Protocols. Int J Oral Maxillofac Implants. 2003;18:250-257.

6) Degidi M, Piattelli A. Immediate Functional and Non-Functional Loading of Dental Implants : A 2-to 60-Month Follow-Up Study of 646 Titanium Implants. J Periodontol 2003;74:225-241.

7) Degidi M, Piattelli A. Comparative analysis study of 702 dental implants subjected to immediate functional loading and immediate nonfunctional loading to traditional healing periods with a follow-up of up to 24 months. Int J Oral Maxillofac Implants 2005;20:99-107.

8) Ericsson I, Nilner K. Early functional loading using branemark dental implants. Int J Periodont Rest Dent 2002;22:9-19.

9) Popper HA, Popper HJ, Popper JP. The Branemark Novum protocol: Description of the treatment procedure and a clinical pilot study of 11 cases. IJPRD 2003;23:459-65.

CorrespondenceAddress: Dr. Kesava Reddy. K Assistant Professor, Dept of Prosthodontics, College of Dental Sciences, Pavilion Road, Davangere, 577004 Karnataka, India. Phone: 91-9480598727 E-mail: [email protected]


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mailto:[email protected]

Abstract

The micro organisms have been implicated in the pathogenesis and progression of pulp and periapical diseases. The

primary objective of endodontic treatment is to remove as many bacteria as possible from the root canal system and

then to create an environment in which any remaining organisms cannot survive .This can only be achieved through the

use of a combination of aseptic treatment techniques, chemo mechanical preparation of the root canal, antimicrobial

irrigating solution and intracanal medicaments. The choice of which intracanal medicament to use is dependent on

having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organism

likely to be involved and their mechanisms of growth and survival. Many medicaments have been used in an attempt to

achieve the above aims, but no single preparation has been formed to be completely predictable or effective. The aim of

this paper is to focus on recent concepts in use of medicaments during endodontic treatment.

Keywords:root canal, medicaments, irrigants, antibiotics, disinfection,

IntroductionMicro organisms play a major role in the development a n d p r o g r e s s i o n o f p u l p a n d p e r i a p i c a l diseases.Bacteria may present in the root canals or in the dentinal tubules, accessory canals, canal rami�ications, apical deltas, �ins and transverse anastomoses. The combination of mechanical instrumentation and irrigating solutions will render 50-

1 70%of infected canals free of micro organisms.Therefore anti microbial agents used as inter-appointment medicaments must be able to penetrate through the dentinal tubules in the presence of microbes to reach a suf�iciently high concentration so that bacteria will be eliminated. Microbial invasion of root canal system is time related and bacterial species dependent.

Commonly seen micro organisms are -bacteroids species -prevotella intermedia -peptostreptococcus microbes -lactobacillus -streptococcus -propionibacterium -E.faecalis

Authors:Dr.L.KrishnaPrasada¹

RecentConceptsInUseOfIntracanalMedicaments.

1. Dr.L.KrishnaprasadaMDS,DNB,MBA College: Professor Dept.of Conservative Dentistry & Endodontics K.V.G.Dental College, Sullia.D.K.574327. Phone:08257-230148 / Mobile;09448012084 E-mail:[email protected]

Intra-canalmedicamentsObjectives: -eliminate or destroy any remaining viable bacteria -reduce periradicular in�lammation -eliminate apical exudates -prevent or arrest in�lammatory resorption -prevent reinfection of root canal system

Typesofintra-canalmedicaments 1. Calcium hydroxide 2. Antibiotics 3. Non-phenolic biocides 4. Phenolic biocides 5. Iodine compounds

CalciumhydroxideCalcium hydroxide has been extensively used in dentistry since 1920s.It has low solubility in

2,3,7water,anhigh pH 12.5-12.8 and insoluble in alcohol.

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Mechanismofaction 1. Chemical action - damage to microbial cytoplasm membrane by the direct action of hydroxyl ion -suppression of enzyme activity -inhibition of DNA replication by splitting DNA 2. Physical action -acting as a physical barrier that �ills the space within the canal and prevents the ingress of bacteria into the canal system -killing the remaining micro organisms by withholding substrates for growth and limiting space for multiplication

The disadvantages of calcium hydroxide are the dif�iculties associated with removing it from the root canal walls and its effect on decreasing the setting times

1,5of zinc oxide based root canal sealers.

AntibioticsThe �irst reported use of an antibiotic in endodontic treatment was in 1951 when Grossman used a polyantibiotic paste known as PBSC.

Commonly used antibiotic containing commercial 7preparations are

- Ledermix paste. ( demeclocycline+triamcinolone)- Septomixine Forte (corticosteroid+neomycin+polymixin B sulphate)- The early use of calcium hydroxide following replantation has been shown to exacerbate replacement resorption due to its high pH and toxicity.- Ledermix paste is the medicament of choice immediately after replantation as it reduces both in�lammatory and replacement resorption.

A 50:50 mixture of Ledermix paste and calcium hydroxide has been advocated as intra-canal medicament in - Infected root canals - Pulp necrosis - Perforations - In�lammatory root resorption - Large periapical radiolucent lesions

Non-phenolicbiocidesBiocides comprise a large group of diverse chemical

agents that are capable of inactivating a variety of micro-organisms.1. Alcohols - ethanol2. Aldehydes - formaldehyde, gluteraldehyde3. Biguanides - chlorhexidine4. Quarternary ammonium compounds5. Zinc 6. Phenolic compounds – essential oils7. Phenyethers - triclosan

While antibiotics affect a speci�ic target site in micro organisms resulting in bacteriostatic and bactericidal effects at therapeutic concentrations, biocides have a broader spectrum of activity as they work on multiple

5, 6 target sites. Hence bacterial resistance to biocides is unlikely to develop. The modes of action ofbiocides include mmembrane damage and leakage, Protein denaturation, Binding of thiol groups, Initiation of autolysis, Congealing of cytoplasm contents at higher concentrations.

FactorsaffectingbiocideactivityConcentrationn Period of contactn pHn Temperaturen Presence of organic matter.

The use of chemical agents like EDTA, polylysine will increase the activity of biocides by increasing the permeability of bacterial cell membranes.

ChlorhexidineIt has reasonably wide range of activity against aerobic and anaerobic organisms as well as Candida species. It is more effective at alkaline than at acid pH, and its action is inhibited by the presence of soaps and organic matter.

MechanismofactionInteraction between the positive charge of the molecule and negatively charged phosphate groups on the bacterial cell wall.

In higher concentrations it is bactericidal due to precipitation and or coagulation of the cytoplasm which is probably caused by protein cross-linking. It should be applied as an medicament between appointments for at least seven days rather than being used only as an irrigant.When used as an


16

intracanal medicament CHX is more effective than calcium hydroxide in eliminating E.faecalis from

6dentinal tubules.

PhenolicagentsThese medicaments have been applied either on a cotton wool pellet placed in the pulp chamber or on a paper point placed in the root canal, with the rationale being that the antimicrobial effect is delivered through vaporization of the medicament. Commonly used phenolic agents are CMCP, Cresatin, Formocresol, Camphorated phenol.CMCP is the most toxic and irritating phenolic antiseptic agent followed by Cresatin, Formocresol, and camphorated phenol. The anti microbial effect is delivered through vaporization of the medicament and the vapor should be in contact with micro –organisms in the canal system. Antibacterial effect may not persist for prolonged periods of time.

IodinecompoundsIodine is rapidly Bactricidal, Fungicidal, Virucidal, Sporicidal.Aqueous iodine solutions are unstable, with molecular iodine being mostly responsible for the antimicrobial activity.Iodophors are complexes of iodine and solubilizing agent or carrier, which acts as a reservoir of the active free iodine.

Modeofactionofiodine --Iodine attacks key groups such as proteins, nucleotides, and fatty acids, resulting in cell death. ---2% preparation of iodine potassium iodide is used in endodontics.

MedicamentvehiclesThe medicament vehicle plays an important role in the overall disinfection process because it determines the velocity of ionic dissociation causing the paste to be solubilized and resorbed at various rates by the periapical tissues and from within the root canal. The lower the viscosity, the higher will be the ionic dissociation.

Typesofpastevehicles1.Watersolublesubstances: Water, saline, local anesthetics, ringers solution, methyl cellulose, etc.Eg: Calxyl, pulpdent

2.Viscousvehicles: Glycerin, polyethylene glycol, propylene glycol. Eg: Ledermix paste.

3.Oilbasedvehicles: Olive oil, silicone oil, camphorweed: Vitapex

Bio�imsBio�ims are composed of micro-colonies of bacterial cells that are non-randomly distributed in a matrix of polysaccharides, proteins, salts and cell material in an aqueous solution. Bacterial bio�ilms are reported to be the most common cause of persistent in�lammation and apical periodontitis.the presence of bio�ilm will affect the ef�icacy of antimicrobial agents since bio�ilms are much more resistant to such agents as result of their diffusion barriers and altered bacterial cell metabolism and replication rates.

1, 7Mechanismofresistanceofbacterialbio�ilms -- The polysaccharide matrix retards diffusion of the antibiotic – Chemical changes to the environment in the bio�ilm where the lack of oxygen inhibits some antibiotics – Protecting them by being located within the interior part of a bio�ilm. – Communication with one another which can in�luence the structure of the bio�ilm by encouraging growth of species bene�icial to bio�ilm. – Depletion of nutrients or accumulation of waste products can result in bacteria entering a non growing state which protects bacteria from the antibiotics – Bio�ilm bacteria existing in a low metabolic state, a slower growth rate and production of exoploysaccharides.

Bio�ilms and microbial aggregates are a common mechanism for the survival of bacteria in nature. The aggregation of bacteria in bio�ilms is likely to result in these bacteria being more resistant to antibiotics and other antimicrobials as well as being protected from the host defenses. It is estimated that bacteria grown in a bio�ilm have a 1000-1500 times greater resistance to antibiotics than planktonically grown bacteria.

During irrigation of root canal, the outer layer of the bio�i lm wil l be directly affected by the high concentration of the irrigating solution, but the extra-cellular matrix of the bio�ilm may prevent the solution p e n e t r a t i n g i n t o t h e d e e p e r l a y e r s a t f u l l strength.Endodntic instrumentation helps to disrupt and expose the full thickness of the bio�ilm to the


17

irrigant solution.

ConclusionBacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. Hence primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. Many intracanal medicaments being tried to achieve these aims but no single preparation has been found to be completely predictable I its ef�icacy and hence much further research is required.

The choice of which intracanal medicament to use during endodntic treatment is dependent on having an accurate diagnosis of the condition being treated. If the primary aim is to reduce in�lammation, then cortico-steroid antibiotic mixture is indicated. Calcium hydroxide and chlorhexidine may be most ideal in infected root canal cases. Further research is required regarding the use of medicaments combined with effects of dentine on single and multiple species bio�ilms.

References1. Abbott PV.Medicaments: aids to success in

endodontics.part 1 .A review of literature.ADJ 1990; 35; 438-448.

2. Orstavik D.Root canal disinfection; a review of concepts and recent developments.ADJ 2003; 29;70-74.

3. Schafer E,Bossmann K.Antimicrobial ef�icacy of chlorhexidine and two calcium hydroxide formulations against Enteroccus faecalis.JOE 2005;31;53-56.

4. Love MR.Enterococcus faecalis –a mechanism for its role in endodontic failure.IEJ 2001; 34; 399-405.

5. Peters OA.Current challenges and concepts in the preparation of root canal systems; a review. JOE 2004; 30; 559-567.

6. Zehnder M.Root canal irrigants.JOE 2006; 32; 389-398.

7. B Athanassiadis, PV Abbott, LJ Walsh. The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodntics.ADJ supplement 2007; 52(1suppl) S64-S82.

CorrespondenceAddress: Dr.L.KrishnaprasadaMDS,DNB,MBA College: Professor Dept.of Conservative Dentistry & Endodontics K.V.G.Dental College, Sullia.D.K.574327. Phone:08257-230148 / Mobile;09448012084 E-mail:[email protected]


18

Abstract

Making of impression for traditional crown and-bridge restorations utilizing materials like polyvinylsiloxane or

polyether has been the standard. But these impressions are not devoid of inaccuracies, thus we require a more accurate

method of replicating the tooth preparations for crowns and bridges. The continuous search for betterment of the

impression making procedure has led to the evolution of the state of the art digital impression technique which has

caused a paradigm shift in the concept of making dental impressions.The various researches have been providing

positive results and announcing the digital impression technology to be very promising. Thus, the digital impressions

can become one of the most powerful and important standards in providing superior �ixed restorations in dentistry.

Keywords: Digital impression devices, Parallel confocal imaging, Active wave front sampling, scanning probe.

IntroductionMaking a �ixed partial impression is probably the most critical step for dentists in the process of creating a superior prosthetic restoration. A perfect impression needs to deliver an exact replica of the clinical situation including a complete void free, and accurate re�lection of

1the margins, ideally on the �irst take .

Though we have the access to a wide range of impression materials, which meets virtually all the requirements and preferences, even the most experienced dentists can encounter dif�iculties in obtaining a precise impression.

Impressions for �ixed prostheses have always been a challenge for both the clinician and the dental lab technician because of the wide range of variables involved.

Clinical problems that negatively impact conventional 1, 2, 3impressions include.

1. Incomplete reproduction of the prepared margins.2. Inadequate tissue management, which fails to

properly isolate the margins.3. Voids in the margins of the impression.

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Authors:M.SunithaRoy.¹,Dr.Soudhamini.V.Rao²,Dr.LakshmipathiReddy.P³

Digitalimpressions,notascience�ictionanymore!

4. Tearing of the margins.5. Light body impression material being displaced by

putty material resulting in loss of sharp surface detail.

6. Distortion of impression from patient movement &/or removal of impression prior to thorough set.

7. Poor bond between tray and impression or putty and light body material.

8. Dental stone casts discrepancies.

We are in the age where patients are extremely concerned about the time and money spent on the aesthetic dental treatments and they ask for the best of the material and technology. Even though we can provide fairly acceptable restorations to the aesthetically demanding patients using conventional impression procedures, time factor also play a crucial factor for patients with hectic schedule.

Fortunately our world of dentistry has been introduced to a new digital impressioning technology, which was virtual has now become a reality.

The technologies that have made the use of three-dimensional (3D) digital scanners an integral part of

1. M.SunithaRoy.MDS Assistant professor, Department of Prosthodontics, K.L.E. Institute of Dental Sciences, Bangalore, Karnataka state, India.

2. Dr.Soudhamini.V.RaoMDS Assistant professor, Department of Prosthodontics, K.L.E. Institute of Dental Sciences, Bangalore, Karnataka state, India.

3. Dr.LakshmipathiReddy.PMDS Assistant professor, Department of Prosthodontics, K.L.E. Institute of Dental Sciences, Bangalore, Karnataka state, India.

many industries for decades have been improved and re�ined for application in dentistry. Since the introduction of the �irst dental impressioning digital scanner in the 1980s, development engineers at a number of companies have enhanced the technologies and created in-of�ice scanners that are increasingly user-friendly and able to produce precisely �itting

4dental restorations.

The digital impression concept is emerging rapidly on the high-tech horizon. Some optimistic proponents infer that digital impressions will solve the challenges now faced with conventional elastomeric impressions.

Commercially available digital impression devices are: The iTero (Cadent, Carlstadt, N.J.) and the Lava Chairside Oral Scanner C.O.S. (3M ESPE, St. Paul, Minn.).

Additionally, the manufacturers of computer-directed in-of�ice milling systems CEREC (SironaDental Systems,

Charlotte, N.C.) and the new E4D system (D4DTechnologies, Richardson, Texas) are working to

provide digital impressions that can be sent to dental 5,6laboratories.

This article reviews the revolutionary digital impression technology, the technique of making digital impression and its pros and cons in comparison to the conventional impression technique.

DigitalimpressiontechnologyThis technology is based on a laser scanning protocol which allows the dentist to take electronic impressions intraorally.

The laser scanning technology presently used in 7

dentistry for intraoral scanning are :

1. Parallel confocal imaging.2. Active wave front sampling.

1. Parallelconfocalimaging(E.g.iTero(Cadent,7 Carlstadt,N.J) :(Fig1)

Parallel confocal imaging uses laser and optical scanning to digitally capture the surface and contours of the tooth and the gingival structure. This type of scanner captures 100,000 points of red laser light and has perfect focus images of more than 300 focal depths of the tooth structure. All of these focal depth images are spaced approximately 50 μm apart. Parallel confocal scanning system

captures all structures and materials found in the oral cavity without the need for scanning powders that coat the teeth.

While the ability of the camera to scan without the

need for powdering may be advantageous, it necessitates the inclusion of a colour wheel into the acquisition unit itself, resulting in a camera with a larger scanner head than the other systems.

2. Act ive wave front sampling (E .g . Lava7C.O.S) :(Fig2)

The method used for capturing 3D impressions involves Active Wave front Sampling. This technology is based on the concept of “3D in Motion” which incorporates revolutionary optical design, image processing algorithms, and real-time model reconstruction to capture 3D data in a video sequence and model the data in real time. The scanning wand contains a complex optical system comprised of multiple lenses and blue LED cells. Thus, it is capable of capturing approximately 20 3D data sets per second, or close to 2,400 data sets per arch, for an accurate and high-speed scan. This technology based system requires enough powdering to allow the scanner to locate the reference points. During the scan, a pulsating blue light emanates from the wand head and an on-screen image of the teeth appears instantaneously.

8,9,10,11Makingofthedigitalimpression :The digital impression system comes with an intra oral scanner that is attached to a monitor which displays the images recorded by the scanner. The system will also have software which helps in reading and analyzing the recorded images. The patients information is entered into the digital prescription form which can be used for future communication with the lab. Once the type of restorative treatment is decided the clinician does the preparation of tooth according to the type of restoration (full metal crown, gold crowns, porcelain fused to metal, all ceramic restoration) to be fabricated.

The prepared tooth requires gingival retraction like any other conventional impression procedure. The margins have to be de�initely exposed, such that it can be scanned and recorded. The double cord gingival retraction technique is better and styptic agent should be used to prevent any gingival bleeding. Before starting with the scanning the upper cord is removed and the prepared


20

tooth should be cleaned of the saliva or any debris.

Digital impression system like lava requires the use of special powder that has to be sprinkled over the prepared tooth before scanning whereas the i-Tero system does not require powdering.

The scanning probe is passed over the prepared tooth which will take a series of images. Once the system identi�ies the tooth to be scanned, it will guide the clinician to scan by voice and visual prompts. The entire scanning process will take about 2 - 3 minutes.

The opposing arch is scanned and also the maxillary and mandibular buccal surface of teeth in centric relation is scanned and the images are transferred onto the monitor.

With the click of a button the entire digital image of the arch of the prepared tooth and also the opposing arch will be constructed in a minute and will be displayed on the computer monitor.

Once the image is constructed the clinician can visualize the scanned digital image in any desired position by rotating the image. One can visualize the occlusal view to evaluate the margins which will help to analyze the preparation for any further modi�ication.

The clinician can visualize the maxillary and mandibular arch in centric relation and check for the amount of tooth reduction (occlusal clearance). One can also check the lingual occlusion. Needed adjustments, if any, are made at this time and a few additional scans will register the changes that were made on the prepared tooth.

The patient can also visualize the digital image on the monitor and the entire ongoing process.

Once the clinician is satis�ied with the digital image of the prepared tooth he/she can send the data directly to the laboratory.

Once the laboratory gets the copy of the digital �ile, the data is fed to the milling machine, which mills the resin model of the digital impression. This resin model is used for fabricating the restoration. Steriolithiograghy technique can also be used for the fabrication of the digital image model.

5,8,9,12,13Advantagesofdigitalimpression :Timefactor: The average time taken for entire process of scanning an average case takes about 2 minutes from start to �inish which is much lesser compared to conventional impression technique.

Givescleardigitalizedimage:This technology has the ability to capture continuous three-dimensional video streams in the mouth and display the data on the touch screen in real time. This enables instant feedback for both the dentist and patient to see the anatomy of the mouth and speci�ic areas of interest.

Dimensional accuracy: There is no scope for distortion of impression as it is a digitalized impression.

Useofimpressiontrayisavoided: Impression trays are not required for digital impressions. Therefore, digital impressions can eliminate the frequently seen problem of separation of impression from the tray.

Clean procedure which is comfortable for thepatienttoo.Gagging can be considerably reduced for the patient.

Prepared tooth can be analyzed better: Digital impression gives better view of the various surfaces of the prepared tooth and the clinician can do any required corrections without making any check cast.

Helpsinpatient'seducation: Patient can view the live images of entire impressioning procedure which can be a source of education to the patient.

Easystorageofdigitaldataforfutureuse: It's easy to store the digital images for future legal reasons or if it requires to repeat the restoration.

Avoidscrosscontamination: Cross contamination is avoided which is of great concern with conventional impression.

5,8,9,12,13DisadvantagesofdigitalimpressionRequirespropertraining: It's a very new technology and it requires one to get familiarized with the digital impression technology.

Requires computer operational knowledge: It requires the clinician to be computer literate.Usedformakingonly�ixedrestorations:Cannot be


21

used to make impressions for complete denture and removable partial denture.

Further research in necessary: Since it's a new technology it still requires long term researches to further validate its accuracy in comparison to conventional impression technique.

Highlyexpensive: Not cost effective.

Requires good tissue management and clean dry �ield: The cameras will record debris, saliva or gingival

hanging over margins which can cause inaccuracies in the resultant digital images.

ConclusionDigital impressions made by using the systems like iTero and Lava Chair side Oral Scanner C.O.S are slowly being

5, 9accepted worldwide . It is being considered as the future of dentistry which can help raise the overall quality of the service we provide to our patients. Various studies done by different researchers have backed this

12, 13, 14, 15state of the art technology .

Digital impressions eliminate some of the negative c h a ra c te r i s t i c s o f c o nve n t i o n a l e l a s to m e r i c impressions, but proper soft-tissue management and isolation of tooth preparation margins are still necessary. These digital impression systems also do not come without a price.

Nevertheless, the digital impression technology is very promising and looks like it's here to stay, however, it requires long term researches to validate its accuracy.

References1. Gordon j . Christensen. The state of � ixed

Prosthodontic impressions. J Am Dent Assoc 2005; 136: 343-6.

2. Luthardt RG, Loss R. Quaas S. Accuracy of intraoral data acquisition in comparison to the conventional impression. 2005; 8:283-94.Int J Comput Dent

3. Gordon J . Christensen. The Chal lenge to Conventional Impressions. Am Dent Assoc 2008; 139:347-49.

4. Henkel GL. A comparison of �ixed prostheses generated from conventional vs digitally scanned Dental impressions. Compend Curr Educ Dentistry 2007; 28:422-31.

5. Birnbaum NS, Aaronson HB. Dental impressions using 3D digital scanners: virtual becomes reality. Compend Contin Educ Dent 2008; 29(8):494-505.

6. Gordon J. Christensen. Will Digital Impressions Eliminate the Current Problems With Conventional Impressions? J Am Dent Assoc2008; 139: 761-763.

7. Nathan S. Birnbaum, Heidi B. Aaronson, Chris Stevens, et al. 3D Digital Scanners: A High-Tech Approach to More Accurate Dental Impressions. 2009 http://www.insidedentistry.net/print. php?id=2682..

8. Scott Henkel. A Closer look at digital impression. Aesthetic dentistry, 2003, 6 (3).

9. CRA foundation. Digital impressions challenge conventional impressions. CRA Newsletter 2007; 31:3-4.

10. Steven Glassman, Digital Impressions for the Fabrication of Aesthetic Ceramic Restorations: A Case Report PPAD 2007; 21:60-4.

11. Product News. British Dental Journal 2009; 206, 598.

12. Robert A. Lowe, Digital Master Impressions: A C l i n i c a l R e a l i t y D e n t a l c o m p a r e . 2 0 0 9 . http://www.dentalcompare.com/featuredarticle.asp?articleID=572.

13. Keating A P, Knox J, Bibb R, Zhurov Ai. A comparison of plaster, digital and reconstructed study model accuracy. J Orthod 2008; 35:191-201.

14. Fasbender DJ .Clinical performance of chair side CAD/ CAM restorations, .J Am dent assoc 2006; 137: 225 – 315.

15. Ireland AJ, McNamara C, Clover MJ, House K, Wenger N, Barbour ME, Alemzadeh K, Zhang L, Sandy JR,. 3D surface imaging in dentistry - what we are looking at. 2008; 11: 205:387-92.Br Dent J.

CorrespondenceAddress: Dr.M.SunithaRoyMDS Assistant professor, Department of Prosthodontics, K.L.E. Institute of Dental Sciences, NO. 20, Yeshwanthpur Suburb, Bangalore - 560022 Karnataka state, India. PHONE NUMBER – 091-9886120415 E-MAIL – [email protected]


22

http://www.insidedentistry.net/print.php?id=2682



http://www.dentalcompare.com/featuredarticle.asp?articleID=572

http://www.dentalcompare.com/featuredarticle.asp?articleID=572

Multiplechoicequestions1) The�irstDentaldigitalimpressioning

technologywasintroducedina) 1990'sb) 2000'sc) 1980'sd) 1970's

2) Whichdigitalimpressioningsystemmakesuseofparallelconfocalimagingtechnology?a) iTerob) Lava c) Bothd) None

3) Whichdigitalimpressioningsystemmakesuseofactivewavefrontsamplingtechnology?a) iTero b) Lavac) Bothd) None

4) Dodigitalimpressionsrequiregingivalretractionofthepreparedtooth?a) Always requires gingival retraction.b) Does not require gingival retraction.c) Required only in All ceramic restorations.d) Required only in metal restorations.

5) Whichscannersystemrequirespowderingofthepreparedtooth?a) iTero systemb) Lava C.OSc) Both d) None

6) Advantagesofdigitalimpressionsincomparisontotheconventionalimpressiontechnique.a) Lesser time required to make the impressionb) Good dimensional accuracyc) Easy storage of the digital data for future used) All of the above

7) Digitalimpressionscanbeusedfora) Removable partial denture.b) Complete denture.c) Fixed partial denture.d) All the above

8) Disadvantagesofdigitalimpressionsincomparisontotheconventionalimpressiontechnique.

a) Can be used only for �ixed restorations b) Not cost effective. c) Requires additional training to use the system. d) All of the above.

9) Whichdigitalsystemhasbiggerscanning wandhead?

a) iTerob) Lava C.O.Sc) Both a and bd) None

10)Digitalimpressionsallowsthecliniciantovisualize a) The prepared tooth b) Maxillary and mandibular arch in centric relation c) The lingual occlusion. d) All of the above

Keyanswers:1.c2.a3.b4.a5.b6.d7.c8.d9.a10.d


23

Abstract

The ectodermal dysplasias are a heterogeneous group of disorders with primary defect in hair, teeth, nail and sweat

gland function. Numerous types have been described and several classi�ications exist. Hypohidrotic ectodermal

dysplasia is a rare congenital disease that affects several ectodermal structures. The condition is usually transmitted as

an x-linked recessive trait, in which gene is carried by the females and manifested in males. Whereas hidrotic

ectodermal dysplasia presents with anomalies such as enamel hypoplasia, hypodontia and facial dysmorphy. In the

developed countries diagnosis of such cases done during childhood. But in the developing countries patients fail to

report for various reasons. Continuous documentation of such conditions therefore remains important in early

diagnosis and better management of these cases.

Keywords:Partial anodontia, Ectodermal dysplasia, Hyperkeratosis, Hidrotic ectodermal dysplasia

KeyMessage: The ectodermal dysplasias are a heterogeneous group of disorders with primary defect in hair, teeth,

nail and sweat gland function.

IntroductionEctodermal Dysplasia is the term used to describe a group of rare, inherited disorder characterized by dysplasia of tissues of ectodermal origin-primarily nail, teeth and skin and occasionally dysplasia of

1mesiodermally derived tissues . It represents a large and complex nosological group of congenital diseases which were �irst described by Thurnam in 1948 and

thlater in the 19 century by Darwin. Its relation to X 2chromosome was determined by Thadani in 1921 . The

condition is thought to occur in approximately 1 of 1, 00, 1, 3000 live births . Ectodermal Dysplasia restricted to

teeth, jaw bones and palms and soles has been reported in past with a very few cases. The etiology is unknown, but consanguinity of parents points to an autosomal recessive inheritance. One such case discussed and reviewed below.

CaseHistoryA 17year old apparently healthy female patient visited our department with a history of missing teeth and wanted to undergo replacement of her missing teeth. Family history revealed that parent's marriage was consanguinal. She has one younger brother and one sister who were normal. On general physical

Authors:Dr.Sujata.M.Byahatti.MDS¹

HidroticEctodermaldysplasia

1. Dr.Sujata.M.Byahatti.MDS (Oral Medicine and Radiology) Department(s) and institution(s): Reader, Department of Oral medicine and Radiology, Maratha Mandals N.G.Halgekar institute of dental sciences and reaserch centre, Belgaum, India

examination she was moderately built and nourished with hyperkeratosis, dryness and crackling of palms and soles (Figure 1, 2, 3, 4, 5). Occasionally she had itching of the skin of the hand when she works with water. The intolerance to cold and heat was not noticed, even the texture of her hair was normal. Patient gives a history that the deciduous teeth were erupted and exfoliated by the age of 7 years. She had complete loss of entire dentition by 8 years. The permanent teeth did not erupt after the exfoliation of deciduous teeth. On intraoral examination, mouth was dry, with completely edentulous upper and lower ridges Figure 6, 7). Her blood report showed that Hb was 9mg/dl. Then she was subjected for radiographic examination where orthopantomography was taken. Orthopantomography shows (Figure 8) impacted 17, 28, and 48 with no evidence of the other tooth buds. With above history, clinical examination and radiographic examination provisional diagnosis of Hidrotic Ectodermal dysplasia was made. In the current case the patient asked to undergo extraction of the impacted teeth followed by denture.

Discussion4Freire Maia and Pinherio described 117 varietiets of

24

Ectodermal Dysplasia with multiple combination of abnormal ectodermally derived structures. These disorders are clinically divided into Hidrotic and Hypohidrotic forms and each of these forms is subdivided into different syndromes based on the p re s e n c e o r a b s e n c e o f h a i r d e fe c t s , t o o t h abnormalities, nail deformities, palmoplantar keratoderma and other features. Hypohidrotic form is X-linked disorder, characterized by the classical triad of hypodontia, hypohydrosis and hypotrichosis and characterized by dysmorphic features is also termed as

5, 6Christ-Siemens Tourine syndrome . The anhidrotic or hypohidrotic form of Ectodermal Dysplasia usually spares the sweat glands, but can affect the teeth, hair, and nail. Cloustan in 1929 and Lowrey et al in 1966 described this as an autosomal dominant, which was

6found in Canadian families of French descent . Ectodermal Dysplasia constitutes a complex group of diseases characterized by various defects in hair, nails, teeth and sweat glands. Several classi�ications exist. Freire Maia and Pinherio have proposed a classi�ication based on the involved ectodermal derivative. In this classi�ication '1' indicates hair dysplasia, '2' dental dysplasia '3' nail dysplasia and '4' sweat gland dysplasia '3' Based on this there are more than 10 subgroups in

7Freire Maia and Pinherio classi�ication . Since our patient had abnormality in teeth, nail it �its into 2-3 subgroup. Ectodermal Dysplasia may cause different forms of disabilities such as different degrees of alopecia and anodontia and severe disabilities such as immunode�iciency and hypohidrosis or anhidrosis,

8which may require continuous palliative management . Thus it may pose serious health problems especially in some societies where marriages within families are

8, 9, 10practiced .

ConclusionThese patients therefore may seek treatment elsewhere such as from traditional healers and may live with such deformities for the lifetime.It can be concluded that lack of correct information and knowledge, results in lack of awareness. It is therefore important to give the correct information regarding causes, disabilities associated with Ectodermal Dysplasia and management options to professionals and society.

Fig 1 Frontal view

Fig 2 Dry, cracked hands-ventral surface

Fig 3 Dry, Cracked hands-Dorsal surface

Fig 4 Dry, Cracked legs-sole


25

Fig 5 Dry, Cracked legs

Fig 6 Upper Edentulous Ridge

Fig 7 Lower Edentulous Ridge

Fig 8 showing Orthopantomography with impacted 17,28,48

References

1. Dhanrajani PJ,Jiffy AO. Managemnet of ectodermal dysplasia. A literature Review. Dental update 1998; 25:73-5.

2. Clarke A.Hypohidrotic ectodermal dysplasia. J Med Genet 1987; 24:659-63.

3. Hodges J, Sarnantha, Harley KE.Witkop tooth and nails syndrome:Report of two cases in a family. Int J Peadiatric Dentistry 1999; 9:207-11.

4. Piegno MA,Blackman RB, Cronin RJ,Cavazos E. Prosthodontic management of ectodermal dysplasia:A review of the Literature. J Prosthet Dent 1996; 76:541-52.

5. Kupietzky K,Milton H.Hypohidrotic ectodermal dysplasia: Characteristics and treatment . Quintessence Int 1995; 26:285-91.

6. Richard AS,Karin V,Gerard K,Caries B,Kournjirn J.Placement of an endoosseous implant in agrowing child with ectodermal dysplasia. Oral surg,Oral Med,Oral Pathol 1993;75:669-73.

7. Itin PH,Fistarol SK, Ectodermal Dysplasia. Am J Med Genet C Semin Med Genet 2004;131c:45-51.

8. Kumar A,Eby MT,Sinha S,Jasmin A,Chaudhary PM. The ectodermal dysplasia receptor activates the nuclear factor-kappa b JNK and cell death pathways and binds to ectodysplasin A. J Bio Chem 2001; 276:2668-77.

9. Suprabha BS. Hereditary ectodermal dysplasia: A case report. J Indian Soc Pedod Prev Dent 2002; 20:37-4.

10. Dof� inger R,Smahi A.Bessia C,geissmann F,Feinberg J,Durandy A, Et al.Xilinked anhidrotic ectodermal dysplasia with immunode�iciency is caused by impaired NF-kappaB signling. Nat Genet 2001; 27:277-85.

CorrespondingAuthor: Dr.Sujata.M.Byahatti Plot no 49, sector # 9, Malmaruti Extn, Belgaum-590016 Phone numbers: Mobile: 9731589981 Res: 08312456931 E-mail address: [email protected]


26

Abstract

The success of a complete denture relies on the principles of retention, stability and support. The prosthodontist's skill

lies in applying these principles ef�iciently in critical situations. Severely resorbed maxillary edentulous ridges that are

narrow and constricted with increased inter ridge space provide decreased support, retention and stability. The

consequent weight of the processed denture only compromises them further. This article describes a case report of an

edentulous patient with resorbed ridges where a simpli�ied technique of fabricating a light weight maxillary complete

denture was used for preservation of denture bearing areas.

Keywords: Complete dentures, hollow maxillary denture, light weight dentures, residual ridge resorption, and inter ridge distance.

IntroductionIt is obvious that in large maxillofacial defects and in severe resorption of the edentulous ridges, there is a decreased denture bearing area for support, retention and stability. Increased interridge space compounds this problem. Therefore in order to decrease the leverage, reduction in the weight of the prosthesis was

1, 2recommended and was also found to be bene�icial . Various weight reduction approaches have been achieved using a solid 3 dimensional spacer, including

1-6 7dental stone , cellophane wrapped asbestos , silicone 8 9putty or modelling clay during laboratory processing

to exclude denture base material from the planned hollow cavity of the prosthesis.

10Fattore et al used a variation of the double �lask technique for obturator fabrication by adding heat polymerizing acrylic resin over the de�initive cast and processing a minimal thickness of acrylic resin around the teeth using a different drag. Both portions of resin were attached using a heat polymerized resin.

8Holt et al processed a shim of acrylic resin over the

27

Authors:Dr.SivaranjaniGali¹,Dr.VibhaShetty²,Dr.SmithaRavindran³

LightWeightMaxillaryCompleteDenture:ACaseReportOfASimpli�iedTechniqueWithThermocole

1. Dr. Sivaranjani Gali, Mds, Senior Lecturer, Department Of Prosthodontics, M S Ramiah Dental College And Hospital, Msrit Campus, Bangalore 5600054. 2. Dr. Vibha Shetty, Mds, Professor And Head, Department Of Prosthodontics, M S Ramiah Dental College And Hospital, Msrit Campus, Bangalore 5600054.

3. Dr. Smitha Ravindran, Post Graduate Student, Department Of Prosthodontics, M S Ramiah Dental College And Hospital, Msrit Campus, Bangalore 5600054

residual ridge and used a spacer. The resin was indexed and the second half of the denture processed against the spacer and the shim. The spacer was then removed and the two halves were luted with auto polymerised acrylic resin using the indices for repositioning. This method has a disadvantage of seepage of �luid into the denture cavity as the junction of the polymerized portions is at the borders.

11Michael O'Sullivan et al described a modi�ied method for fabricating a hollow maxillary denture. An impression of the trial denture base was made and a stone cast was poured. A clear matrix of the stone cast was made. The trial denture base was then invested in the conventional manner till the wax elimination. A 2mm heat polymerized acrylic resin shim was made on the master cast using a second �lask. Silicone putty was placed over the shim and its thickness was estimated using the clear template. The original �lask with the teeth was then placed over the putty and the shim and the processing was done. Later the putty was removed from the distal end of the denture and the openings were sealed with the auto polymerizing resin.

The technique was useful in estimation of the spacer thickness, but the removal of the putty was found to be dif�icult especially from the anterior portion of the denture. Moreover, the openings made form the distal end has to be made suf�iciently large to retrieve the hard putty which will decrease the strength of the denture.

This article describes a case report of a 45 year old edentulous male patient with increased interridge distance where in a simpli�ied method using thermocole, a common packing material, was used as the spacer for the fabrication of light weight maxillary denture.

CaseReport:A 45 year old patient walked into the dental clinic with a chief complaint of replacing missing teeth. He has been edentulous for about 10 years and has been wearing denture since 7 years. On examination, he had severely resorbed ridges, the upper being narrow and constricted and with an interridge space between the maxillary and mandibular edentulous arches of about 38 mm as ahown in �igure 1. The patient had no other abnormalities in relation to temperomandibular joints.

Because of narrow constricted ridges and increased interridge distance, a criss cross teeth arrangement ( with the lower right posterior teeth placed on the upper left posterior ridge and lower left posterior teeth placed on the upper right posterior teeth) was planned for better stability as the forces are directed better towards the ridges and a light weight maxillary complete denture was also planned to counteract the lateral forces better and decrease the leverage by reducing the weight of the maxillary denture.

Technique1. Keeping in mind the strength of the denture, the

distance from the teeth to the 3mm of the denture base was calculated. The rest of the denture base till the borders was then calculated as shown in �igures 2 and 3. Therefore the spacer would occupy the area between the shim of 2mm thickness and teeth with 3mm of the denture base.

2. The trial denture base was invested and regular procedure carried out till the wax elimination stage. Two layers of hard baseplate wax over the de�initive cast in the drag(lower half of the �lask or the cast side) conforming to the border extensions was added as shown in �igure 4.

3. A second �lask was used to invest the baseplate wax till the wax elimination stage and the cope (upper half of the �lask or cavity side) was packed and processed with the heat polymerizing resin.

4. The second cope with the polymerized acrylic resin shim of 2mm attached with the drag was separated. A denser type of thermo Cole was placed over the bur roughened acrylic shim along the ridge and luted with cyanoacrylate as shown in �igure 5.

5. The spacer thickness was modi�ied according to the calculation done above leaving 3mm from the teeth to the denture base.

6. The original cope over the drag was reseated and complete closure of the �lask was later veri�ied. The heat polymerizing resin was then mixed, packed and

0processed at 74 C for 7-8 hours. Pre insertion occlusal corrections were made and after the necessary corrections, the denture was inserted in the patient's mouth as shown in �igure 6 and 7.

Fig-1

Fig-2


28

Fig-3

Fig-4

Fig-5

Fig-6

Fig-7

DiscussionThe method described has advantages over the previously described techniques. Thermocole being a light weight material can be left in the denture without retrieving it thereby not compromising the intergrity of the denture. Therefore the tedious effort to remove the spacer material from the denture can be avoided. Moreover the small window in the cameo surface in the previous techniques always has a small margin for leakage between the heat polymerized resin and auto polymerized resin portions. This technique allows the control of the spacer thickness and is also very simple to execute.

SummaryA simpli�ied technique for fabricating a light weight maxillary denture is described. The technique uses a light weight packing material thermocole as the spacer that can be left in the denture without compromising the denture strength.

References1. El Mahdy AS. Processing a hollow obturator.J

Prosthet Dent 1969; 22:682-6.2. Brown KE.Fabrication of a hollow bulb obturator. J

Prosthet Dent 1969; 21:97-103.3. Ackermann AJ.Prosthetic management of oral and

facial defects following cancer surgery. J Prosthet Dent 1955; 5:413-32.

4. Nidiffer TJ, Shipman TH.Hollow bulb obturator for acquired palatal openings. J Prosthet Dent 1957; 7:126-34.

5. Rahn AO, Boucher LJ.Maxillofacial prosthetics: principles and concepts.St .Louis: Elsevier; 1970.p.95.


29

6. Chalian VA, Drane JB, Standish SM.Intraoral prosthetics.In:Chalian VA, Drane JB,Standish S M , e d i t o r s . M a x i l l o f a c i a l P r o s t h e t i c s : multidisciplinary practice.Baltimore:Williams & Wilkins;1971.p.133-57.

7. Worley JL, Kneijski ME.A method for controlling the thickness of hollow obturator prosthesis Prosthet Dent 1983; 50:227-9.

8. Holt RA Jr.A hollow complete lower denture. J Prosthet Dent 1981; 45:452-4.

9. Da Breo EL.A light cured interim obturator prosthesis. A clinical report. J Prosthet Dent 1990; 63:371-3.

10. Fattore LD, Fine L et al.The hollow denture: an alternative treatment for atrophic maxillae Prosthet Dent 1988; 59:514-6.

11. Micheal O'Sullivan, Nancy Hansen, Robert J.Cronin et al.The hollow maxillary complete denture: A modi�ied technique. J Prosthet Dent 2004; 91:591-4.

CorrespondingAuthor Dr.SivaranjaniGali, Mds, Senior Lecturer, Department Of Prosthodontics, M S Ramiah Dental College And Hospital, Msrit Campus, New Bel Road, Bangalore 5600054. Telephone -080-23602079, Ext No -27 Mobile-09880152494 Fax-080-2360185 [email protected]


30

Abstract

This study evaluated the presence of microorganisms in dental rubber bowls and the effectiveness of three different

disinfectants at various time intervals after disinfection of rubber bowls.

MaterialsandMethods

The dental rubber bowls were swabbed before, immediately after its use in patients, after 5 and 10 min of spray disinfection with Glutaraldehyde, Sodium Hypochlorite and Isopropyl alcohol. The swabs were sent for microbial growth culture and analysis was performed.

Results

There was scanty to heavy growth of either positive cocci or positive bacilli before and after washing the rubber bowl. No growth of microbes was seen after 5 and 10 minutes with all the spray disinfectants.

Conclusion

There was absolutely no growth of microorganisms after 5 and 10 minutes of disinfection of dental rubber bowl. This procedure should be mandatorily performed to prevent cross-infection.

Keywords:Dental mixing rubber bowl, Disinfectants, Spray

IntroductionProsthodontic patients, especially those requiring treatment with a removable prosthesis need several appointments. These patients are generally a high risk group relative to their potential to transmit infectious

1diseases as well as acquire them . The cross- infection control guide published by the British Dental Association states that “the only safe approach to routine treatment is to assume that every patient may be

2a carrier of an infectious disease” . Therefore it becomes essential to be aware regarding the cross-infection control measures in dental practice.

In the process of fabrication of removable prosthesis, a prosthodontist needs to use many dental instruments and equipments which add to the risk of disease transmission to the clinics because of the infection spreading through the contaminated lab equipments. Many studies have proved the contamination and the effective methods of disinfection on impressions, casts,

3,4pumice etc , but not much of literature is available on the contamination and disinfection of dental rubber

31

Authors:Dr.Rajeswari.C.L.¹,Dr.Srivatsa.G.²

1. Dr.RAJESWARI.C.L.M.D.S Professor Department of Prosthodontics KLE Society's Institute of Dental Sciences Bangalore.

AnevaluationoftheeffectivenessofvariousdisinfectantsonthemicroorganismspresentinDentalrubberbowls

2. Dr.SRIVATSA.G.M.D.S Professor & Principal Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bangalore.

bowl.

Hence, this study was undertaken to evaluate the ef�icacy of three commercially available disinfectants Glutaraldehyde, Sodium Hypochlorite and Isopropyl Alcohol on dental rubber bowl in preventing transmission of infections.

MaterialsandMethods

Dental rubber bowls were randomly selected for the study from those which were being used on patient procedures like jaw relation and placement of removable prosthesis.

The sterile swabs was taken and swiped on the used dental rubber bowl before and after washing with sterile water. Two more swabs were collected after 5 and 10 minutes of spray disinfection.

Disinfectants used were grouped as, (Fig.1)

Group A: 2% Glutaraldehyde

Group B: 1:10 dilution of 5.25% Sodium Hypochlorite (fresh solution)

Group C: Isopropyl Alcohol

The manufacturers instructions were followed for spray disinfection at 5 and 10 minute intervals. Once the rubber bowls were spray disinfected, they were kept in zip lock plastic bags (Fig. 2)

The swabs were inoculated in nutrient Agar medium, and the plates were incubated in an incubator for 24 hours at 37°C. Jar was incubated for micro-aerophilic organisms. The plates were read for presence of microorganisms. Organisms were con�irmed by doing the Gram- staining and biochemical reaction. (Fig. 3).

Fig.-1 Different disinfectants in the spray bottles

Fig.-2 : Sprayed disinfectants dental rubber bowl in the zip lock plastic bag

Fig.-3 Microbial cultures growth on the nutrient Agar medium plates

ResultsThere was scanty to heavy deposition of Gram Positive cocci and Gram positive bacilli both before and after washing the rubber bowls. After spraying of disinfectants Glutaraldehyde (Group A), Sodium Hypochlorite (Group B) and Isopropyl Alcohol (Group C) for 5 and 10 minute intervals, there was no growth of either Gram Positive cocci or bacilli. The results were found to be statistically signi�icant as per Friedman's Test (P= 0.001) (Table No. 1).

Groups

Intervals N Mean

Std.

Deviation

Chi-square

value P value A BW 12 1.92 0.669 32.116 0.001

AW 12 1.33 0.985

5 min 12 0.00 0.000

10 min 12 0.00 0.000 B BW 12 1.67 0.778 35.040 0.001

AW 12 1.33 0.492

5 min 12 0.00 0.000

10 min 12 0.00 0.000C BW 12 1.00 0.000 29.143 0.001

AW 12 0.82 0.405

5 min 12 0.00 0.000

10 min 12 0.00 0.000

P � 0.05 (Statistically signicant)

Tables&Graphs:

Table No. 1: The mean, Standard deviation, chi-square

value of the difference among the Groups using

friedman's test.


32

Groups

AW - BW

5 min -

BW

10 min. -

BW

5 min -

AW

10 min. -

AW

10 min. -

5 min

A

2× value -2.070 -3.134 -3.134 -2.873 -2.873 0.000

Asymp. Sig.

(2-tailed)

* * * *0.038 0.002 0.002 0.004 0.004* 1.000

B

2× value -2.000 -3.115 -3.115 -3.176 -3.176 0.000

Asymp. Sig.

(2-tailed)

* * * *0.046 0.002 0.002 0.001 0.001* 1.000

C

2× value -1.414 -3.317 -3.317 -3.162 -3.162 0.000

Asymp. Sig.

(2-tailed)

* * *0.157 0.001 0.001 0.002 0.002* 1.000

2× = Wilcoxon rank test, *P � 0.05 (Statistically signicant)

Graph 1: Microorganisms present before and after

wash, after 5 and 10 min of disinfection using

Group A,B & C.

Note: BW= Before wash, AW=After wash,

PC= Positive cocci, PB= Positive Bacilli, A= After,

Dis= Disinfection

On further analysis using Wilcoxon Rank Test to assess the difference between each interval, it was found to be statistically signi�icant between all the intervals except for between 10 and 5 minutes for all the groups A, B & C (P= 0.001) and, after and before wash for Group C (P= 0.001). (Table No. 2)

Table No. 2: Difference within the groups using

Wilcoxon rank test

DiscussionThe fabrication of dental prostheses involves the use of many instruments in the clinic as well as dental laboratory. Hence, it becomes mandatory to follow the disinfection protocol as a part of standard precautions and safe work practices. The most important phase is the pre-sterilizing stage wherein thorough cleaning of records, equipments etc. that have contacted the oral tissues has to be performed with running water. Apart from this, application of a diluted detergent and further rinsing must continue until all visible contamination is removed.

It is generally recognized that disposable materials 5should be used whenever possible , but many of the

instruments and equipments which are not disposable need to be sterilized. Disinfectants must be used to decontaminate non-sterilizable instruments like shade and mould guides, mixing spatulas, wax knives, occlusal plane indicators, articulators, facebows, and other

3,4maxillomandibular registration apparatus . Ideally, they should be cleaned thoroughly in an ultrasonic bath before being sterilized in an autoclave. Out of two general approaches to surface asepsis, cleaning and disinfecting contaminated surface was followed in this study.

According to Miller and Palenik in 1994, chemicals used for surface and equipment asepsis are- Chlorine, e.g. sodium hypochlorite- Phenolic compounds —(a) Water based - water with ortho- phenyl phenol or

tertiary amylphenol or O benzyl p- chlorophenol(b) Alcohol based - Ethyl or iso propyl alocohol with O

phenyl phenol or tertiary amylphenol(C) Iodophor - butoxypoly propoxy poly ethoxy

6,7ethanol iodine complex

The BDA recommends 70% isopropyl alcohol, hypochlorite solution (containing 1% available chlorine), or 2% glutaraldehyde solution for disinfecting

8contaminated surfaces under different circumstances.

In this study three disinfectants Glutaraldehyde (Group A), Sodium Hypochlorite (Group B) and Isopropyl Alcohol (Group C) were chosen to disinfect the rubber bowls. The selected disinfectants were easy to use, consume less time and less expensive than the other methods like the use of autoclave, ethylene oxide gas,

9,10radiation, low UV intensity irradiation .

All the disinfectants used to sterilize the rubber bowls in this study proved equally effective after disinfecting for 5 and 10 minutes. Within the groups, the values were statistically signi�icant with p=0.001 for group A, B and C by using Friedman's test (Table-1). When the differences within the group was compared using Wilcoxon rank test, it was found to be statistically signi�icant within 10 and 5 min group for all the disinfectants (p=0.000). The remaining groups were found to be non-signi�icant (Table -2).


33

Rinsing is considered bene�icial as it removes organic debris that may prevent exposure of the surface to the disinfectant and compromises their activity. Rinsing also reduces the load of viruses and bacteria. In this study, it was observed that before wash, there was scanty to heavy growth of both positive cocci and positive bacilli in all the groups. Even after wash, there was moderate to scanty presence of both positive cocci and positive bacilli in all the groups. This was in concordant with some of the studies done by Bergman

11 12 13 1989 , McNeill 1992 and Beyerle 1994 where they proved that the bacteria were removed by only 40% to 90% just by washing with water on the impressions.

The ef�icacy of a disinfectant depends on suf�icient length of treatment time, effective concentration of the disinfectant and on the method used: immersion, spray, or intermediate. There was absolutely no growth of positive cocci and positive bacilli in all the groups after disinfecting the rubber bowls for 5 and 10 minutes with all the disinfectant solutions (Graph-1). Even though certain studies proved the recommended time to be 10 minutes of spray disinfection, in this study, even 5 minutes of spray disinfection in all the groups is equally effective to 10 minutes of disinfection. This could be explained on the basis that the surface was smoother and the material was rubber, compared to other equipments like trays, facebow, denture bases, etc. which are rougher and irregular

14surfaces .

In this study, all the disinfectants proved equally effective and it was similar to a study conducted by Jennings et al. in the year 1991, which also concluded that Glutaraldehyde and Sodium Hypochlorite

15exhibited comparable microbiocidal activity .

According to et al, there was found to be Jachuck SJallergic reactions to 2% alkaline glutaraldehyde like a signi�icant excess of nasal and throat symptoms, nausea and headache, and rashes on the hands among the medical personnel. Bronchial provocation testing in one worker showed a late asthmatic reaction to 2% alkaline glutaraldehyde suggesting an allergic rather than an irritant reaction. Several other sterilizing agents also cause occupational asthma, rhinitis, or dermatitis-for example, formaldehyde, chlorhexidine,

16, 17isothiazolinones, and chloramine . One needs to follow the recommendations for the use of safety

measures, as well as carefully follow the disinfection techniques.

It is clinically recommended to use any of the three disinfectants tested in this study and spray on the rubber bowls used on patients for at least 5 minutes to prevent cross contamination. Further studies are advised to test the complete microbial �lora on rubber bowls and test the ef�icacy of various disinfectants.

ConclusionWithin the limitations of the study, it was concluded that: 1. There was scanty to heavy growth of both Gram positive cocci and Gram positive bacilli in all the groups before and as well as after wash of the rubber bowls.2. There was absolutely no growth of Gram positive cocci and Gram positive bacilli in all the groups after disinfecting the rubber bowls for 5 and 10 minutes with all the three disinfectant solution sprays.References1. C Connor. Cross-contamination control in

prosthodontic practice. International Journal of Prosthodontics, 1991;4:337-344.

2. Watkinson AC. Disinfection of Impressions in UK Dental Schools. Br Dent J 1988; 164: 22-23.

3. Jisa Ann Alex, Sudhir N, Taruna M, Ramu Reddy. Infection control in Prosthodontics. Indian J Dent Adv 2016; 8(1): 41-45

4. Vidya S. Bhat, Mallika S. Shetty, Kamalakanth K. Shenoy. Infection control in the prosthodontic laboratory - JIPS 2007;7:62-65.

5. Farzaneh Firoozeh, Mohammad Zibaei, Abolfazl Zendedel, Hushang Rashidipour, Aziz Kamran. Microbiological study pumice used in dental laboratories. Journal of Medical Research 2013;2(2):123-7.

6. Neeraj Rampal, Salil Pawah, Pankaj Kaushik. Infection control in Prosthodontics. J Oral Health Comm Dent 2010;4(1):7-11.

7. Siddharth Phull, Arvind Arora and Yashendra. Sterilization and disinfection in Prosthodontics. Indian Journal of Dental Sciences 2014;6(4):112-6.

8. Siddharth Phull, Arvind Arora & Yashendra. Sterilization & disinfection in Prosthodontics. 2014;6(4):112-6.

9. R. Oliver. The sterilization of surgical rubber gloves and plastic tubing by means of ionizing radiation. J. Hyg., Camb. 1960; 58: 465 -472.


34

https://www.ncbi.nlm.nih.gov/pubmed/?term=Jachuck%20SJ%5BAuthor%5D&cauthor=true&cauthor_uid=2525652

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http://search.ebscohost.com/login.aspx?direct=true&profile=ehost&scope=site&authtype=crawler&jrnl=08932174&AN=37703052&h=DIrwuR9k10BGOWNCOyZB7r1h30CznWbeGo2gphiKNHajC93CXz1esb8AJe%2FQdvFH5DP9oGWemVKSGdhbDs8Wpw%3D%3D&crl=c

10. Reley DJ , , , Bavastrello V Covani U Barone A Nicolini C. An in-vitro study of the sterilization of titanium dental implants using low intensity UV-radiation. Dent Mater. 2005 Aug;21(8):756-60.

11. Bergman B: Disinfection of Prosthodontic impression materials: A literature review. Int J Prosthodont; 1989;2:537-42.

12. McNeill MR, Coulter WA, Hussey DL: Disinfection of irreversible hydrocolloid impressions: a comparative study. Int J Prosthodont 1992 ; 5(6):563-7.

13. Beyerle MP, Hensley DM, Bradley DV Jr., Schwartz RS, Hilton TJ: Immersion disinfection of irreversible hydrocolloid impressions with sodium hypochlorite. Part I: Microbiology. Int J Prosthodont; 1994;7(3):234-8.

14. Samaranayake LP, Meena H, Jennings KJ: Carriage of oral �lora on irreversible hydrocolloid and elastomeric impression materials. J Prosthet Dent ;1991;65:244-9.

15. Jennings KJ, Samaranayake L:. The persistence of microorganisms on impression materials following disinfection. Int J Prosthodont; 1991;4:382-7.

16. P Sherwood Burgeo. Occupational risks of glutaraldehyde, May cause respiratory, nasal, and skin problems at low concentration BMJ 1989;299(5):342.

17. Jachuck SJ , , . Bound CL Steel J Blain PGOccupational hazard in hospital staff exposed to 2 per cent glutaraldehyde in an endoscopy unit. J Soc Occup Med. 1989;39(2):69-71.

CorrespondenceAddressDr.RAJESWARI.C.LProfessor Department of ProsthodonticsKLE Society's Institute of Dental SciencesOpp CMTI, No. 20, Tumkur RoadYeshwanthpur suburbBangalore- 560022Phone no: 9448262048 e-mail: [email protected]


35

https://www.ncbi.nlm.nih.gov/pubmed/?term=Bavastrello%20V%5BAuthor%5D&cauthor=true&cauthor_uid=15878616

https://www.ncbi.nlm.nih.gov/pubmed/?term=Covani%20U%5BAuthor%5D&cauthor=true&cauthor_uid=15878616

https://www.ncbi.nlm.nih.gov/pubmed/?term=Barone%20A%5BAuthor%5D&cauthor=true&cauthor_uid=15878616

https://www.ncbi.nlm.nih.gov/pubmed/?term=Nicolini%20C%5BAuthor%5D&cauthor=true&cauthor_uid=15878616

https://www.ncbi.nlm.nih.gov/pubmed/?term=Nicolini%20C%5BAuthor%5D&cauthor=true&cauthor_uid=15878616

https://www.ncbi.nlm.nih.gov/pubmed/15878616

https://www.ncbi.nlm.nih.gov/pubmed/?term=Bound%20CL%5BAuthor%5D&cauthor=true&cauthor_uid=2525652

https://www.ncbi.nlm.nih.gov/pubmed/?term=Steel%20J%5BAuthor%5D&cauthor=true&cauthor_uid=2525652

https://www.ncbi.nlm.nih.gov/pubmed/?term=Blain%20PG%5BAuthor%5D&cauthor=true&cauthor_uid=2525652



Abstract

One of the popular means to treat the partially edentulous patient to restore oral function and esthetics is by 1,2,9fabrication of an acrylic partial denture . A very important requirement for a removable partial denture is that it

should not cause any damage to the underlying tissues.

An acrylic partial denture is supposed to be a temporary prosthesis and may harm the integrity of adjacent teeth and 3health of supporting tissues, if worn for extended periods without supportive care . Of considerable concern are

reports that many patients expressed satisfaction with these dentures, in spite of the fact that their dental health had 4deteriorated markedly . As we continue to use this prosthesis in this manner, it is better to know a few more points

about them so that their ill effects are minimized.

Keywords:Temporary removable partial dentures, Acrylic removable partial dentures, partially edentulous

IntroductionThe acrylic removable partial denture is actually referred to as interim denture and is to be used for short

3planned interval of time . It is a tissue borne prosthesis and the vertical load is received directly by the mucosa without any assistance from the natural teeth. It may be braced against lateral loads by the lingual surfaces and interproximal embrasures of the remaining teeth and the proximal surfaces of the teeth adjacent to the edentulous spaces. Some teeth may also be �itted with clasps. Retention can also be gained due to physical factors between the denture base and the tissues and by neuromuscular factors.

AdvantagesofacrylicRPDsŸ They are economicalŸ They are possible in all edentulous casesŸ Esthetically they are as good as any other type of

prosthesisŸ Minimal preparation of natural teeth.Ÿ Possibly less complicated procedures involved. So

they are simple and faster to fabricate.Ÿ They are more easily repaired and can have additions

made to them.

Authors:Dr.Srivatsa.G¹,Dr.RohitShetty²

1. Dr.SRIVATSA.G M.D.S [Prosthodontics] Professor and HOD Department of Prosthodontics, KLE Society's institute of dental sciences, Bangalore. Phone no 080-23528228 [R] / 9845449452 [M] e-mail: srivatsa.g @ rediffmail.com

AcrylicRemovablePartialDentures-MinimizingDamageToTheTissues

2. Dr.ROHITSHETTY M.D.S [Prosthodontics] Professor KLE Society's institute of dental sciences, Bangalore.

DisadvantagesŸ In these mucosa-supported dentures, the forces are

only compressive in nature and are transmitted over a more restricted area. As they lack vertical support, sooner or later, they sink due to the resorption of the ridge.

Ÿ Being tissue borne, there is movement of these dentures.

Ÿ As they are thick and occupy more space, there is feeling of bulkiness and speech problem. Debris and plaque may collect beneath the denture base and the tissues.

Ÿ They cannot withstand much masticatory load.

Causesfordamagetothetissues Ÿ They can cause caries and periodontal problem, by

harboring plaque and food debris in close contact with the natural teeth and gingiva. Prolonged marginal gingivitis can lead to chronic periodontal disease and teeth mobility. The lack of vertical support and the movement of the denture tend to cause stripping of the gingival margin and damage to the mucous membrane and the ridge. The above factors are considered mainly responsible for

6, 7periodontal breakdown with these dentures .

36

Ÿ They may loosen the natural teeth by leverage caused by clasps gripping the teeth too tightly for retention of prosthesis.

The de�initive choice of treatment for partially edentulous patients is either a �ixed partial or a cast partial denture. But for such patients who cannot afford them, the choice is limited to acrylic removable partial dentures. To justify such a prosthesis, which can be harmful to the patient, the need for such a treatment must be established and every effort must be made to

5prevent its ill-effects .

The objective of this article it to describe in detail the precautions to be taken during different stages of its construction and use, to minimize this damage.

Minimizingdamagetothetissues1. Educate the patient about cast RPD and the

limitations of acrylic RPD including risks. Patient should understand the importance of hygiene maintenance and post-insertion checkups.

2. Restorethehealthoftheremainingtissues�irst.The goal is to eliminate disease and treat any defect that hinders plaque control, and create a better environment for cleaning. RPD treatment should follow extractions, periodontal, conservative, endodontic and crown and bridge treatment.

3. Prepareandsurveydiagnosticcasts.Study the occlusal plane and relationship. Identify undercuts, do block out and obtain the tilt of the cast parallel to the path of insertion of the partial denture. Surveying helps in outlining the denture border and in retentive clasp placement.

4. Follow optimal design. Bilateral design and maximum extension provides for better retention and stability to the dentures, wider force distribution and optimum vertical support.

Occlusal rests can be incorporated by bending a

piece of wrought wire to engage the occlusal surfaces of at least one posterior tooth on both sides of the arch to provide resistance to vertical displacement.

5. Mouth preparation. Mouth preparation is minimal and includes correction of occlusal plane if necessary and elimination of gross undercuts [greater than 0.30 inch] on the surfaces of the teeth to be contacted by the denture base. Selected proximal teeth surfaces can be made parallel to

provide guiding planes.6. Claspdesign.Clasps are optional for these dentures

and should be avoided as far as possible unless the retentive factors are unfavorable. Proper extension and adaptation should in most cases provide adequate retention.

If a clasp is given, select periodontally strong teeth and locate the undercuts. Round wrought wires of 18 gauge and simple circlet clasps are used.

Follow the principles of clasp design and adjustment. Adjusting the clasp to increase retention is not by forcing it towards the tooth, but by contouring it to engage a deeper part of the retentive undercut. The clasp arm should remain passive and act only when the denture is being lifted.

7. Makegoodimpressions.When one or two teeth are being replaced, a single impression of alginate with a stock tray is enough. Make sure that the impression has recorded accurately the entire denture bearing area included in the design. It is of utmost importance to record the functional depth of the sulci. The impression tray may require modi�ications with wax. The tray may also be adapted and correctly extended in the edentulous region by �illing that part of it with impression compound. This acts as a special tray for alginate.

If extensive edentulous space exists or in distal extension situations, a dual impression is required to be made with the help of the special tray. This is necessary to achieve maximum area coverage and desired tissue placement.

8. Jaw relation recording and articulation. If suf�icient numbers of natural teeth are present, a simple opposition of casts can be done by occluding the remaining teeth and mounted on the articulator.

When there are suf�icient natural teeth occluding but the opposing natural teeth cannot be occluded in a stable position on the casts, jaw relations are recorded in the existing vertical dimension and occlusion using partial record blocks. e.g. distal extension, long edentulous span.

When there are not suf�icient opposing natural teeth,

jaw relations need to be recorded with the occlusal rims as in a complete denture patient.


37

9. Labprocedures. The gingival and ridge contours around the

adjacent natural teeth should be used as a guide to develop contours around the arti�icial teeth. If little or no resorption has taken place, the neck of the teeth can be butted directly against the ridge and labial �lange avoided, to make them “gum �it”.

During wax up, the part of the denture base, which �it against the crowns of the natural teeth is to be placed above the survey line. This ensures that the denture �its snugly against the teeth when the undercuts are relieved. This does not leave a gap into which food debris may pack, a fault, which is commonly seen.

DentureprocessingProcessing acrylic RPDs is many times a challenging task. Breakage of the remaining teeth and investing plaster, and shifting of arti�icial teeth and clasps is commonly encountered during dewaxing and packing. Undercuts around the remaining teeth need to be handled very carefully to correctly reproduce the form of the denture.

10.Insertion. I n s e r t i o n a p p o i n t m e n t i n c l u d e s c a re f u l

adjustments for complete placement, occlusal correction, and patient education. If surveyed and well designed and if the impression and lab procedures have been carried out correctly, the prosthesis will go to position with a snap sound. Otherwise the prosthesis can hardly be inserted and many times frustrate the operator.

The most common areas that will interfere with the seating of the denture are the interproximal projections between the natural teeth and the contact areas of the arti�icial teeth with the proximal surfaces of the natural teeth adjacent to the edentulous space. This can be checked with the carbon paper placed against the impression surface. The denture should be inserted gently and only slight pressure applied after resistance to seating is encountered. The carbon marks will be visible in the areas of interference. The interfering areas when relieved carefully ensure better seating of the denture. The alterations at each trial insertion should be kept minimal to avoid over trimming. Check the denture �lange as a possible area of interference with pressure indicating paste. There should be

intimate contact between the edges of the denture base and the soft tissue.

Once the complete seating is ensured check for the occlusion and the clasps for their position and relation with respect to the undercut and gingival margin.

12. Occlusion. The occlusion in the arti�icial dentition must be

made to harmonize with the natural occlusion in centric and eccentric positions. Ensure that the contact of the natural teeth is the same with or without the denture. Use of carbon paper and celluloid strips can check the occlusion. A denture with heavy contacts or which opens the vertical dimension results in entire load applied on denture and causes damage to the underlying tissues.

13. Instructions.Teach the method of insertion and removal to the patient, in front of hand mirror. The hygiene measures should include denture rinsing, brushing after each meal, and the use of interdental brushes. A higher level of oral hygiene with these measures can help keep the plaque

10level low . Instruct regarding night rest for the underlying tissues and importance of regular checkups.

14. Postinsertioncheckups. All the clinical studies have clearly emphasized

the need for frequent recall and maintenance for 10,11patients wearing RPDs . It includes evaluation

of the prosthesis, the response of oral tissues and acceptance of prosthesis by the patient. Check for maintenance of hygiene, rocking and looseness, redness, caries, periodontal status and loss of occlusal contact.

SummaryandConclusionIf the prosthetic treatment is carefully planned, good plaque control established and maintained, and a rigorous recall regime is in place, RPDs result in

12minimal alteration to the teeth and the soft tissues .

Bene�its from the prosthesis should outweigh risks. Otherwise the cases may be best left without dentures. Assess the following prior to RPD fabrication.- Has the missing teeth impaired patients' functions

or will it do it later- If the occlusion of the teeth is such that there very


38

little possibility of overeruption or tooth drift occurring

- If mastication is ef�icient with the remaining natural teeth

- If appearance and speech are not adversely effected

- Is the patient able to understand the prosthesis and if he can and will maintain oral hygiene

Ill designed RPDs associated with improper post placement care results in gum strippers and painless extractors. Hence, the single mostimportant factor to be considered whiletreating with acrylic removable partialdentures is themaintenanceof thehealthofremainingtissues.

References1. Budtz-Jorgensen E. Restoration of the partially

e d e n t u l o u s m o u t h - A c o m p a r i s o n o f overdentures, removable partial dentures, �ixed partial dentures and implant treatment. J Dent 1996;24:237-244

2. Thean HP, Payne JA, Jeganathan S. The use of removable partial dentures amongst private dental practitioners in Singapore. Singapore Dent J 1996;21:26-30

3. McGinvey, Glen. McCracken's removable partial prosthodontics, ed. 9, Mosby Company, 1985.

4. Stewart L Kenneth. Clinical removable partial denture, ed. 2, Ishiyaka Euro America, Tokyo, 1997.

5. Bergman B. Periodontal reactions related to RPDs: a literature review. J Prosthet Dent. 1987;58:454-458

6. Carlsson GE, Hedegard B, Koiumaa KK. Studies in partial dental prosthesis. IV. Final results of a 4-year longitudinal investigation of dentogingivally supported partial dentures. Acta Odontol Scand 1965; 23: 443-472

7. Dyer M. The 'Every' type acrylic partial denture. Dent Pract 1972;22:339-341.

8. Chamrawy E, Runov J. Offsetting the increased plaque formation in partial denture wearers by tooth brushing. J Oral Rehabil 1979; 6: 399-403

9. Theyer HH, Kratochvil FJ. Symposium on periodontal restorative interrelationships. Periodontal considerations with removable partial dentures. Dent Clin North Am 1980: 24: 357-368

10. Bergman B, Hugoson A, Olsson CO. A 25 year longitudinal study of patients treated with removable partial dentures, J Oral Rehabil 1995; 22: 595-599

11. Damien W almsley A. Acrylic partial dentures. Dent Update 2003: 30: 424-429

12. Davenport J.C, Basker R M, Heath J R, Ralph J P and Glantz P O. The removable partial denture equation. Br Dent J 2000; 189: 414-424

CorrespondenceAddress:

Dr.SRIVATSA.G M.D.S [Prosthodontics] Professor and HOD Department of Prosthodontics, KLE Society's institute of dental sciences, Bangalore. Phone no 080-23528228 [R] / 9845449452 [M] e-mail: srivatsa.g @ rediffmail.com


39

Abstract

BackgroundandObjective: Objective of current study is to determine the usefulness of orthopantomograph, for early

diagnosis of osteoporosis. Osteoporosis is a major health problem for elderly male and postmenopausal women.

Osteoporosis can result in bone fracture especially of spine and hip and loss of height often seen in osteoporotic

postmenopausal women. The panoramic radiograph showing progressive periodontal disease, alveolar bone

resorption, tooth loss and endosteal resorption of the mandibular inferior cortex and reduced mandibular cortical

width (MCW), may indicate general osteoporosis.

MaterialandMethods: This study was done by measuring the MCW on 750 Orthopantomograph at the level of mental

foramen. Three readings were taken each side, bilaterally; using digital vernier caliper. Averages of 6 readings were

calculated. Chi-square test, student's 't' test and regression analysis were done.

Results: There was a signi�icant reduction in MCW of elder subjects than younger subjects. There was a marked

reduction in MCW of elderly females than that of elderly males. The MCW was negatively correlated with age.

Conclusion: Oral radiologists have got an important role in screening individuals for osteoporosis. Signi�icant

numbers of patients with osteoporosis are visiting dental institutions. Simple visual estimation of mandibular inferior

cortex on panoramic radiograph helps for identifying adults prone for osteoporosis. Suspected patients can be referred

to physician, for the �inal diagnosis and treatment. Thus orthopantomograph can contribute for early diagnosis of the

systemic disease, osteoporosis.

Key Words: Bone Mineral Density, Mandibular Cortical Width, Osteoporosis, Orthopantomograph, Panoramic

radiograph.

IntroductionOsteoporosis is a generalized decrease of bone mass in

[1]which the histological appearance of bone is normal. Osteoporosis is a metabolic bone disease characterized by low bone mass and micro architectural deterioration of bone tissue, leading to enhanced bone fragility, compromised bone strength and a consequent increase

[2] in fracture risk. Many patients with osteoporosis are seeking dental treatment who are unaware of the underlying disease. Oral physicians can play an important role in early diagnosis of the disease.

In India, it is found that 29.9% of women and 24.3% of men aged between 20 and 79 years had low bone mass, furthermore, about 50% women and 36% of men over 50 years of age were noted to have low bone mass. There

Authors:Dr.ShobhaB.Sikkerimath¹,Dr.Ramesh²

StudyontheusefulnessofOrthopantomographforearlydiagnosisofosteoporosis

1. Dr.ShobhaB.Sikkerimath Department of Oral Medicine and Dental Radiology, P.M.N.M. Dental College and Hospital, Bagalkot, Karnataka, India.

2. Dr.Ramesh Principal and Head , department of Oral medicine and radiology, Navodaya dental college and hospital, Raichur, Karnataka, India.

is higher prevalence of low bone mass in the Indian [3]population compared to the western population.

Osteoporosis can be primary and secondary. Primary occurs with aging process. Bone mass normally increases from infancy to about 35-40 years of age. After 40 years there begins a gradual and progressive decline at the rate of about 8% per

[1]decade in women and 3% per decade in men. Women are at high risk (according to WHO 30%) in t h e i r p o s t m e n o p a u s a l p h a s e . S e c o n d a r y osteoporosis occurs due to renal disease and Cushing's syndrome. Whatever the cause, the consequences of osteoporosis are devasting and can leads to illness, pain, functional limitation reduced

40

quality of life; skeletal bone fracture and even death.Dentists can increase their patient's knowledge about osteoporosis and its risk factors and refer their patient to physician for the �inal diagnosis, and treatment

[4]when systemic bone loss is suspected. In the oral cavity, osteoporosis leads to early tooth loss, excessive alveolar ridge resorption, chronic destructive periodontal disease, referred maxillary sinus pain, or fracture. Radiographic features are loss of lamina Dura, resorption of residual ridge, reduction in the

[5]number of trabeculae and reduced bone mass.

There are many bone mineral density [BMD] measurement techniques, including radiophotometry, photodensitometry, Quantitative analysis of bone trabeculae, digital subtraction photon absorptiometry, and quantitative computed tomography (QCT).

MaterialAndMethodThe study population consisted of 900 panoramic radiographs of the adult patients, who came for their routine dental health problem. Study conducted in the Department of Oral medicine and Dental Radiology, during the year 2004 to 2007 for the period of three years. Data were recorded in the specially prepared case history p r o f o r m a f r o m t h e p a t i e n t s a n d Orthopantomograph [OPG] were taken.

Inclusion criteria: Age of the patients ranged from 21 years and above. A total of 750 good radiographs selected from 900 radiographs.

Exclusioncriteria:The patients with metabolic disorders, local lesions affecting the mandibular cortex, hormonal therapy and drugs affecting general bone metabolism were excluded from the study. Out of 900 OPG's, 150 OPG's were further eliminated because of the faulty radiographs, indistinct mental foramina.

The subjects were categorized under 2 groups. Group I consisted of the subject's age ranging from 21 to 40 years. Group II consisted of the subject's age ranging from 41 years and above. Then both the groups were subdivided into male and female groups.

The bone mineral density of mandible was assessed by measuring Mandibular cortical width [MCW] at the level of mental foramen, on both right and left sides, by using a digital vernier caliper (Mitutoyo Digimatic caliper, Japan) [Fig 1]. Radiograph placed on viewer, a total of six readings, three readings on each side were taken. All six readings were averaged for each patient. Statistical analysis were done using students't' test, chi- square test and regression analysis.

ResultsA total of 750 patients were studied. The mean age in group I was 28.35 and in group II it was 54.26 [Table 1]. The mean of MCW in group I was 4.81. Mean MCW of Younger male subjects was 5.13 mm and younger females subjects was 4.54 mm. In group II, the mean MCW for total subjects was found 3.86 mm, whereas for males and females it was 4.15 mm and 3.50 mm respectively [Graph 1].

A signi�icant difference is found between younger male and female subjects with respect to MCW (t = 8.41, P < 0.01), at 1% level of signi�icance. It means that younger male subjects have higher MCW value (5.12 mm), than younger female subjects (4.53 mm) [Table 2]. A signi�icant difference is found between elder males and elder females subjects with respect to MCW (t = 5.54, P < 0.01) at 1% level of signi�icance. It shows that elder male subjects have higher MCW than elder females [Table 3].

A signi�icant difference is found between younger and elder male subjects with respect to MCW values, (t = 10.88, P < 0.01) at 1% level of signi�icance. It means that younger male subjects have higher MCW value (5.12 mm), than elder males (4.15 mm) [Table 4].

A signi�icant difference is also found between younger and elder female subjects with respect to MCW values (t = 11.25, P < 0.01) at 1% level of signi�icance, which means that younger female subjects have got higher MCW (4.54 mm) than elder females (3.50 mm) [Table 5].

Correlation analysis was done between age and MCW. There is signi�icant negative correlation observed between MCW with age (r = -0.4145 [Table 6]. The regression analysis was done to know the impact of age on MCW. In total samples it was found to be negative


41

and signi�icant at 1% level of signi�icance [Table 7] [Graph 2]. The regression analysis in males and females was found to be negative and signi�icant at 1% level of signi�icance.

Table1:MeanofMCWbyagegroupandsex.

Characters

Summary

Age in yrs

Group I (21-40)

Group II (41yrs & above)

Male

Female

Total

Male

Female Total

n

215

241

456

159

135 294

Age

Mean

28.71

28.03

28.35

55.08

53.29 54.26

SD

6.13

6.32

6.23

10.10

9.60 9.90

MCW

Mean 5.13 4.54 4.81 4.15 3.50 3.86

SD 0.81 0.70 0.81 0.91 1.08 1.04

Variable Sex n Mean SD t-value p-value Signi.

Age

Male

215

28.7116

6.1318

1.1604 0.2465 NS

Female

241

28.0332

6.3205

MCW

Male 215 5.1280 0.8084

8.4173 0.0000 S

Female 241 4.5350 0.6957

Table2:ComparisonofmaleandfemalesubjectsingroupIwithrespecttoMCW.

Table3:ComparisonofmaleandfemalesubjectsingroupIIwithrespecttoMCW.

Variable

Sex n Mean SD t-value p-value Signi.

Age

Male

159

55.0818 10.1007

1.5511 0.1220 NS

Female

135

53.2889 9.6048

MCW

Male 159 4.1544 0.9148

5.5953 0.0000 S

Female 135 3.5047 1.0762

Variable Age[Yrs] n Mean SD t-value p-value Signi.

MCW

Group I [21-40]

215

5.1280

0.8084

10.8835 0.0000 S

Group II 41+ 159 4.1544 0.9148

Variable Age[Yrs]

n

Mean

SD t-value p-value Signi.

MCW

Group I [21-40]

241

4.5350

0.8084

11.25 < 0.01 S

Group II 41+ 135 3.5047 0.9148

Table4:ComparisonofmalesubjectsingroupIandIIwithrespecttoMCW.

Table5:ComparisonoffemalesubjectsingroupIandIIwithrespecttoMCW.

Table6:CorrelationanalysisbetweenageandMCWvalues(Total).

Age

MCW

MCW

-0.4145* 1.0000

* indicates significant at 5% (p<0.05) level of significance

Variable

Beta SE of beta Reg coefficient SE of Reg Coef. t-value p-level Signi

Intercept

5.5307

0.0940 58.8539 0.0000 S

Age

-0.4145

0.0333

-0.0284

0.0023 -12.4575 0.0000 S

R=0.4145, R²=0.1718, Adjusted R²=0.1707, F(1,748)=155.19 p<0.00000, S, Std.Error of es�mate:0 .9283

Table7:Regressioncoef�icientofageonMCWvalues(Total)

Fig.1 showing measurement of MCW on OPG using caliperse.

Graph1:showingaveragevaluesofMCWbyagegroup


42

Graph2.RegressionanalysisshowingimpactofageonMCW[Total]

DiscussionApproximately 99% of total body weight of calcium is present in the skeleton. It is lost by body through several mechanisms. Women loose additional calcium due to several factors, like pregnancy, lactation and loss of estrogen at menopause. Any loss of calcium results in loss of bone density resulting in

[6]osteoporosis.

Many studies support the concept that BMD of [7]mandible is indeed correlated with the skeletal BMD.

In comparison with peripheral BMD measurement equipment in the medical �ield, the dentist will be able to identify osteoporotic individuals by means of dental panoramic radiographs taken for routine dental problem without additional cost.

In our study, we measured the MCW on panoramic radiograph, which is clearly seen on this radiograph.

[5, 8-16]Many other investigators have also used [9]panoramic radiographs to measure MCW. Brass et al

introduced measurement of MCW at the angle of mandible as an index. The angular cortex is very narrow anatomically, frequently unde�ined because of the superimposition of airway shadow and horizontal magni�ication on panoramic radiographs will also in�luence measurement at this site.

[17]Yang measured MCW from the premolar to molar region on OPG. Because the vertical magni�ication is less in�luenced by positioning or operating error in panoramic radiography, the height of the mandibular cortical zone in this site shows rather stable values. Yang used the teeth as landmarks, so Yang index cannot be used in edentulous subjects. Therefore in our study we used the mental foramen as the landmark because, there is no masticatory muscular

[5],in�luence less superimposition compared to that of [8]angular cortex , and the distance between lower

border of mandible to mental foramen remains relatively constant when compared to distance between mental foramen and superior border of residual ridge in spite of resorption of alveolar process

[18]above foramen . QCT has been adopted by few [15, 17, 19- 20]authors . Although QCT gives an accurate

measurement of bone density, it is not available everywhere and is very expensive. Hence we measured the MCW, which is more closely related with the

[8- 9, 13-mandibular BMD evaluated by QCT. Many authors 15, 21-24] have also used the MCW to measure the BMD.

[8]Akira Taguchi found that there was high correlation between the left and right MCW values, which indicates that only unilateral measurements can be used. But we measured MCW values on both right and left side, taking three readings each side to overcome the errors during technique. Furthermore we took maximum sample size about 900 panoramic radiographs.

In our study we have used digital vernier calipers to measure MCW, which gives most accurate reading till 0.0001 mm width. It will also avoid any inaccuracies in

[8- 9]readings and also time saving. There are studies done using vernier calipers, marking gauze, scale etc.

In our study average value of MCW in younger males was more than younger females which was consistent

[8]with the values of study done by Akira Taguchi , in which males had slightly more MCW value than same age group females. He felt that this may be because of hormonal variation in females. The average MCW of younger subjects was more than that of elder subjects, which was also consistent with study done by Akira Taguchi, which may be because of negative correlation of MCW with age. The MCW of elder females was signi�icantly less than that of same age group males. This was consistent with the values of study by Akira Taguchi. He felt that this may be because of postmenopausal syndrome in elderly females in addition to aging process.

[25]Daniel stated that if poor dental habits were the only major cause of tooth loss in late adulthood, a much greater frequency of edentulism would be expected among men than women, because of less attention paid to dental hygiene by men. It was strongly suggested that postmenopausal osteoporosis might be the additional


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cause of the tooth loss in elderly women.

Few authors found that there is a signi�icant correlation between metacarpal index and rapidity of bone loss score in female group. The osteoporosis starts in women at 35 years of age whereas in men after 45 years in�luences the rate of alveolar bone loss in elder female group.

[26]J.J. Groen found that there is a signi�icant and frequent c o - o c c u r r e n c e o f p e r i o d o n t a l d i s e a s e a n d p o s t m e n o p a u s a l o s t e o p o r o s i s ( p r e - s e n i l e osteoporosis). With the use of metacarpal index, Daniel [26] [27], Wactawaski suggested that general osteoporosis might contribute to tooth loss in postmenopausal women, which leads to reduced MCW.

There is high negative correlation observed between MCW with age. We consider that the decrease in MCW in the elder female group contributed to tooth loss after menopause, which leads to alveolar bone atrophy. It is also possible that the decrease in mandibular bone mass is result of tooth loss and increased mobility of teeth. The osteoporosis of mandible is more important

[6]contributor to tooth loss . It is possible that the oral physician may estimate the future risk of mobility and tooth loss in individuals with periodontitis and

[22]osteoporosis by dental panoramic radiographs . There by oral physician can aid in the early diagnosis of a systemic disease, osteoporosis.

As advanced methods of measuring BMD are not easily available and affordable, we used Orthopantomograph to measure the MCW, to assess the osteoporosis in large series of patients who were attending dental OPD. We felt that it is easiest, simplest, inexpensive, non-invasive and an easily accessible dental technique for detection of osteoporosis. Hence dental panoramic radiographs can be used as tool to detect osteoporosis. Panoramic radiographs further can be digitized transmitted for further opinions, and treatment planning.

AcknowledgementWe are thankful to Dr. Siddanna M Patted, MS (Ortho), Associate Professor, S. N Medical College, Bagalkot and Dr. Basavaraj Sikkerimath, Professor, Dept of Oral and Maxillofacial Surgery, P.M.N.M Dental College and Hospital, Bagalkot for their valuable guidance and timely help during the study.

Referance1. White SC, Pharoah MJ. Oral radiology, principles

and interpretation. 4th edn. St Louis: Mosby. A Harcourt Health Sciences Company. 2000:480-1.

2. Rosier RN, Bukata SV. Chapter 16, Bone metabolism and metabolic bone disease. American Academy of Orthopaedic Surgeons, Orthopaedic knowledge Update 7. Jaypee Brothers Medical Publishers. 2002:141-54.

3. CIMS – The �irst serm for the prevention and treatment of postmenopausal osteoporosis. CIMS – 86, Suppliment update 2004; 3-July: 3-4.

4. Marjorie KJ, Charles HC. Systemic osteoporosis and oral bone loss: Evidence shows increased risk factors. JADA 1993; 124: 49-55.

5. Byron WB, Thomas JP, Birgit JG, Dallas and San A. Variation in adult cortical bone mass as measured by a panoramic mandibular index. Oral Surg Oral Med Oral Pathol 1991; 71: 349-56.

6. Crystal BJ. Relationship of osteoporosis to excessive residual ridge resorption. The J Prosthet Dent 1981; 46: 123-5.

7. Kribbs PG, Chesnut CH, Ott SM, Kilcyne RF. Relationship between mandibular and skeletal bone in a population of normal women. J Prosthet Dent 1990; 67: 86-9.

8. Akira T, Keiji T, Yoshikazu S, Takuro W. Tooth loss and mandibular osteopenia. Oral Surg Oral Med Oral Pathol Oral Radiol Oral Endod 1995; 79: 127-32.

9. Bross J, Von Ooij CP, Inpijn LA, Kusen GJ and Wilmink JM, Radiographic interpretation of the mandibular angular cortex: A diagnostic tool in metabolic bone loss. J Oral Surg 1982;53:541-5.

10. Kenneth EW, Charles CS. Studies of residual ridge resorption, Part I. Use of panoramic radiographs for evaluation and classi�ication of mandibular resorption. J Prosthet Dent 1974; 32: 7-12.

11. Ortman LF, Houseman E and Dunford RG. Skeletal osteopenia and residual ridge resorption. J Prosthet Dent 1989; 61: 321-5.

12. Klemetti E, Kolmakor S, Heiskanen P, Vainio P, Lassila V. Panoramic mandibular index and bone mineral densities in postmenopausal women. Oral Surg Oral Med Oral Pathol 1993; 75: 774-9.

13. Watson EL, Katz RV, Adelezzi R, Gift HC, Dunn SM. The measurement of mandibular cortical bone height in osteoporotic vs non-osteoporotic postmenopausal women. Spee Care Dentist 1995; 15: 124-8.


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14. Taguchi A, Suei Y, Ohtsuka M, Otani K, Tanimoto K, Ohtani M. Usefulness of panoramic radiography in the diagnosis of postmenopausal osteoporosis in women. Width and morphology of inferior cortex of the mandible. Dentomaxillofacial Radiol 1996; 25: 263-7.

15. Klemetti E, Kalmakow S. Morphology of the mandibular cortex on panoramic radiographs as an indicator of bone quality. Dentomaxillofac Radiol 1997; 26: 22-5.

16. Bollen AM, Taguchi A, Hujoel PP, Hollender LG. Number of teeth and residual alveolar ridge height in subjects with a history of self-reposted osteoporotic fractures. Osteoporos Int 2004; 15: 970-4.

17. Harry KG, Christopher EC, Bruce E, Gilbert SG. Quantitative computed tomography of vertebral spongiosa, a sensitive method for detecting early bone loss after oophorectomy. Annals of Internal Medicine 1982; 97: 699-705.

18. Charles IN, Sol B. The signi�icance of age changes in human alveolar mucosa and bone. The Journal of Prosthet Dent 1978; 39: 495-501.

19. Bassi F, Procchio M, Fava C, Schierano G, Preti G. Bone density in human dentate and edentulous mandibles using computed tomography. Oral Implants Res 1999; 10: 356-61.

20. Taguchi A. The basic study on measurement on bone mineral density of mandible with dual energy quantitative computed tomography. J Hiroshima Univ Dent Soc 1992; 24: 18-38.

21. Taguchi A, Suei Y, Sanada M, Ohtsuka M, Nakamoto T, Sumida H et al. Validation of dental panoramic r a d i o g r a p hy m e a s u r e s f o r i d e n t i f y i n g p o s t m e n o p a u s a l w o m e n w i t h s p i n a l osteoporosis. AJR AM J Roentgenol 2004; 18: 1755-60.

22. Tozum TF, Taguchi A. Role of dental panoramic radiographs in assessment of future dental conditions in patients with osteoporosis and periodontitis. N Y State Dent J 2004; 70: 32-5.

23. White SC, Taguchi A, Kao D, Wu S, Service SK, Yoon D. Clinical and panoramic predictors of femur bone mineral density. Osteoporosis Int 2005; 16: 339-46.

24. Lee K, Taguchi A, Ishii K, Suei Y, Fujita M, Nakamoto T et al. Visual assessment of the mandibular cortex on panoramic radiographic to identify postmenopausal women with low bone mineral densities. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2005; 100: 226-31.

25. Daniel HW. Postmenopausal tooth loss: contributions to edentulism by osteoporosis and cigarette smoking. Arch Internal Medicine 1983; 143: 1678-82.

26. Groen JJ, Menczel and Shapiro J. Chronic destructive periodontal disease in patients with pre senile osteoporosis. J Periodontol 1968; 39: 19-23.

27. Wactawski WJ, Grossi SG, Trevissan M. The role of osteopenia in periodontal disease. J Periodontol 1996; 67: 1076-84.

CorrespondenceAddress: Dr. Shobha B Sikkerimath, Assistant Professor,

c/o Dr. Basavaraj Sikkerimath, Dental Staff Quarters, H No: 17, B.V.V.S.Campus,

Bagalkot-587101, Karnataka, India. EmailID:[email protected],

[email protected]. Cell no: +91 9902599936, +91 9448326864.


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Authors:Dr.AjayGDoni¹,Dr.SupriyaManvi²,Dr.RajeswariC.L³,Dr.RohitMohanShetty⁴,Dr.SrivatsaG⁵,Dr.DeeptiKumar⁶

GuidingMandibleBackHome:ProstheticRehabilitation:CaseReport

Abstract

Surgical resection of the mandible due to presence of benign or malignant tumour is the most common cause of the

mandibular deviation. The resection can be total or segmental depending on the lesion. Loss of mandibular continuity

results in deviation of the remaining mandibular segment towards the resected side, primarily because of the loss of

tissue involved in the surgical resection. The success in rehabilitating a patient with hemimandibulectomy depends

upon the nature and extent of the surgical defect, treatment plan, type of prosthesis, and patient co-operation. The

earlier the mandibular guidance therapy is initiated in the course of treatment, the more successful is the patient's

de�initive occlusal relationship. Prosthodontic treatment coupled with an exercise program helps in reducing

mandibular deviation and improving the masticatory ef�iciency. This case report describes an early prosthodontic

management of a patient who has undergone hemimandibulectomy and was rehabilitated using provisional guide

�lange prosthesis followed by a de�initive maxillary and mandibular cast partial denture with precision attachments

that was designed to ful�il patient's needs.

Keywords:Guide �lange prosthesis, Hemimandibulectomy, Maxillofacial prosthesis, Rehabilitation.

IntroductionOdontogenic tumours of epithelial origin are usually seen in the posterior mandible and are often treated with surgical excision.1 Cantor and Curtis have classi�ied hemimandibulectomy for edentulous patients that can be applied in partially edentulous arches. Mandibular discontinuity due to hemimandibulectomy leads to one of the most common sequelae i.e; deviation of mandible to the resected side and other dysfunctions such as dif�iculty in mastication, swallowing, speech, mandibular movements, and even respiration.²

Mandibulectomy with radical neck dissection increases the probability of this deviation. This leads to facial dis�igurement, loss of occlusal contact, loss of lip

1. Dr.AjayGDoni Post Graduate Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

2. Dr.SupriyaManvi Professor Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

3. Dr.RajeswariC.L Professor Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

4. Dr.RohitMohanShetty Professor & Head of the Department Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

5. Dr.SrivatsaG Professor and Principal Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

6. Dr.DeeptiKumar Post Graduate Department of Prosthodontics, KLE Society's Institute of Dental Sciences, Bengaluru.

competency for saliva control and to initiate the swallowing process in many cases.1 During the initial healing period prosthodontic intervention is required for preventing the mandibular deviation. Literature shows techniques to correct mandibular deviation that can vary from intermaxillary �ixation with elastics to palatal or mandibular guiding �lange prosthesis anchored on natural teeth or the denture �lange.2 The guide �lange prosthesis is probably the simplest and most useful aid in maintaining the position of the remaining jaw.³

This case report describes an early prosthodontic management of a patient who has undergone hemimandibulectomy and was rehabilitated using provisional guide �lange prosthesis followed by a


47

de�initive maxillary and mandibular cast partial denture with precision attachments that was designed to ful�il patient's needs and requirements.

CaseReportA 58 year-old, female patient was referred to the Department of Prosthodontics from the Department of oral and maxillofacial surgery (KLE Dental College, Bengaluru) for correction of deviated mandible and deranged occlusion 2 weeks post-operatively. Upon eliciting the history, the patient had undergone hemimandibulectomy for squamous cell carcinoma of left side of the mandible, distal to the lateral incisor upto left condyle and hence was classi�ied under Cantor and Curtis classi�ication-II. Clinical evaluation revealed restricted mouth opening of almost 20 mm, with gross asymmetry of the left side of face. There was a deviation of 15 mm of the mandible toward the left side from the midline. The region starting from the left lower bicuspid up to the left condyle was excised. Remaining dentition was sound with a total of 21 teeth present. Oral hygiene was poor with in�lamed gingiva and the left buccal mucosa showed a satisfactory healing. Occlusion was completely deranged with the right lower cuspid occluding in between the upper central incisors (Fig1). Associated problems included dif�iculty in speech, swallowing and mastication, dis�igurement of face.

Fig1.a)Extraoralviewshowingdeviatedmandibletotheleft(resectedside).

Fig.1b)Intraoralviewshowingmidlineshifttotheleft.

Treatmentsteps1. Midline of the lower third of face was marked

using an indelible pencil on both the maxilla and mandible and impressions were made using an elastomeric impression material (Fig.2).

2. Interocclusal bite registration material was used to record the patientʼs existing occlusion.

3. Casts were poured with Type III gypsum material and mounted on an articulator with the teeth in maximum intercuspation.

4. A 19-gauge stainless steel wire was adapted extending from the lingual surface of 45 and 46 interdentally extending occlusally upto the buccal surface of 15 and 16 forming a loop. An additional Adams clasp was made over the right mandibular molar to enhance retention.

5. Modeling wax was used to stabilize the wire. 6. A layer of separating medium was applied on the

surface of the cast followed by addition of autopolymerizing resin (DPI clear; Dental Products of India, Mumbai) of suf�icient thickness on the right maxillary buccal and mandibular lingual region. Care was taken to ensure that the material did not extend over the occlusal surfaces and that the articulator was closed with the casts in occlusion during the setting of the material.

7. Once the material was set, the prosthesis was removed, �inished and polished before evaluating its �it in the patientʼs mouth (Fig.3).

8. The patient was then trained to insert the mandibular portion of the prosthesis and to slowly close as the extension of the prosthesis into the maxillary buccal region or the buccal �lange guides the mandible into maxillary buccal region or the buccal �lange guides the mandible in to complete occlusion. (Fig.4)


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9. The midline was once again assessed to check that it coincides. (Fig.5) 10. Patient was instructed to wear the prosthesis for

eight hours a day, removing it only while having food and during sleep.

Two months post insertion, the patient was able to effectively close her mandible into maximum intercuspation without the use of the guide �lange (Fig.6).

Fig 2. Impressions

Fig 3. Guide �lange prosthesis

Fig 4. Note the guiding �lange on the maxillary right posterior teeth.

Fig 5. Intraoral view, and note the correction of the deviation and midline.

Fig 6.(a) Extraoral view 2 months postoperative

Fig 6.(b) Note the occlusion and midline.

Discussion Depending upon the location and extent of the tumour in the mandible, various surgical treatment modalities like marginal, segmental, hemi, subtotal, or total mandibulectomy can be performed. Loss of mandibular continuity causes deviation of remaining mandibular segment(s) toward the defect and rotation of the mandibular occlusal plane inferiorly.4 The usual result of the mandibular resection with disarticulation is a shift of the residual fragment to the resected side. This mandibular shift is due to the uncompensated in�luence of the contra-lateral musculature, particularly the internal pterygoid muscle. If this in�luence is left uncompensated, the contraction of the cicatricial tissue on the operated side will �ix the residual fragment in its deviated position.5 This situation leads to facial deformity and functional loss.

Though fabrication of de�initve prosthesis is the �inal solution for replacing the missing teeth for reconstructed mandibulectomy patients, the

clinicians must wait for extensive period of time for completion of healing and acceptance of the osseous graft . During this initial healing period early prosthodontic intervention by mandibular guide �lange and maxillary stabilization prosthesis serve the purpose of reducing the mandibular deviation, preventing extrusion of the maxillary teeth and improving the masticatory ef�iciency. Our principal aim was to maintain her aesthetics during mandibular movements. Hence the guide �lange prosthesis was fabricated in clear acrylic resin and the retentive wire components were kept distal to the mandibular canine to minimize the prosthesis display. A vertical extension from the buccal aspect of a mandibular prosthesis extends to contact the buccal surface of the opposing maxillary teeth. This extension maintains the mandible in the proper mediolateral position for vertical chewing, but little, if any, lateral movement is possible.

This clinical report illustrates the prosthetic management of a patient who underwent mandibular resection due to surgery for squamous cell carcinoma. Adell etal6 have carried out a retrospective evaluation to evaluate the possibility of providing every patient with dental rehabilitation after segmental resections and primary jaw reconstructions. Osseointegrated implants are the more recent and advanced treatment modality for craniofacial reconstruction. However, they require extensive period for healing and acceptance of graft and are expensive. Thus, more immediate and economical means of prosthetic rehabilitation are preferred by most patients. The literature shows various types of cast metal guidance prostheses which are effective in managing the mandibular deviation.7 But such appliances are complex, the technique is sensitive and costly and they require a number of patient visits. The acrylic guide �lange prosthesis which is presented here is a simple and cost effective method for managing the mandibular deviation. The number of patient visits is also less as compared to the cast metal guidance prosthesis. The other advantage is it's ease of adjustability.

The success of mandibular guidance therapy depends on the early beginning, the nature of the surgical defect and the patient's cooperation. Mandibular guidance therapy begins when the immediate postsurgical sequelae have subsided, usually within 2 to 3 weeks after surgery. This sort of therapy is most successful in patients whose resection involves only bone structures

and minimally the tongue, the �loor of the mouth and contiguous soft tissues. The presence of the teeth in both the arches is important for the effective guidance and the reprogramming of the mandibular movements. The patient in this clinical report retained all her teeth, except those on the defect site. Therefore, the patient had a better proprioceptive sense and was able to achieve the functional position after the insertion of the prosthesis.

The main purpose is to re-educate the mandibular muscles to re-establish an acceptable occlusal relationship (physiotherapeutic function) for the residual hemimandible, so that the patient can control the opening and closing of the mandibular movements adequately and repeatedly. This is the beginning of an accomplished prosthetic rehabilitation by using a removable prosthesis, by which arti�icial teeth could warrant a stable occlusion. For better results, the prosthetic management can be combined with an exercise program that can be started 2 weeks after the surgery. On opening completely, the mandible can be displaced by hand as forcefully as possible towards the nonsurgical side. These movements tend to lessen scar c o n t r a c t u r e , r e d u c e t r i s m u s , a n d i m p r o v e maxillomandibular relationships.

ConclusionThe prognosis of the prosthesis in functional rehabilitation of hemimandibulectomy patient who has undergone resection without reconstruction is guarded. Guide �lange prosthesis is most common treatment modality. However, in cases where suf�icient numbers of abutment teeth are not present and where deviation is massive, providing twin occlusion rehabilitates the patient functionally. Surgical reconstruction by implants and grafts of various types is the ideal treatment when feasible. However, it is not always feasible in every patient , alternative prosthodontic approach has to be considered to restore the esthetics and function in such subject.

References

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1. BeumerJ, CurtisT,FirtellD, editors. Maxillofacial rehabilitation.St Louis: Mosby 1979;90-169

2. Cantor R, Curtis TA. Prosthetic management of edentulous mandibulectomy patients. Part1. A n a to m i c , p hys i o lo g i c a n d p syc h o lo g i c consideration. J Prosthet Dent 1971; 25:446-457

3. Schneider RL, Taylor TO. Mandibular resection uidance prosthesis: a literature review. J Prosthet

Dent 1986; 55:84-86 4. Taylor TD. Diagnostic considerations for

p r o s t h o d o n t i c r e h a b i l i t a t i o n o f t h e mandibulectomy patient. In: Taylor TD, editor. Clinical maxillofacial prosthetics. Chicago: Quintessence Publishing; 2000. pp. 155–170.

5. Gupta SG, Sandhu D, Arora A, Pasam N. The use of mandibular guidance prosthesis to correct m a n d i b u l a r d e v i a t i o n f o l l o w i n g hemimnadibulectomy - Case reports. Indian J Dent Res Rev. 2012; 2:71–3.

6. Adell, Ragnar & Svensson, Börje & Bågenholm, Torun. (2008). Dental rehabilitation in 101 primarily reconstructed jaws after segmental resections – Possibilities and problems. An 18-year study. Journal of cranio-maxillo-facial surgery: of�icial publication of the European Association for Cranio-Maxillo-Facial Surgery. 36. 395-402. 10.1016/j.jcms.2007.11.006.

7. Babu, S., Manjunath, S., & Vajawat, M. (2016). De�initive guiding �lange prosthesis: A de�initive approach in segmental mandibulectomy defect. Dental research journal, 13(3), 292–295. doi:10.4103/1735-3327.182192.

CorrespondingAddress Dr.AjayGDoni Post Graduate, Department of Prosthodontics KLE Society's Institute of Dental Sciences, #20, Tumkur Main Rd, Yeshwanthpur Suburb II Stage, Raja Industrial Estate, Yeswanthpur, Bengaluru, Karnataka 560022. Contact No – 9108762972 Email – [email protected]

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