7/30/2019 _pdf321

1/7

Infuence o Endodontic Irrigants on Resin Sealer BondStrength to Radicular Dentin

Aline Wunderlich Rocha, Cntia Dickel de Andrade,Vicente Castelo Branco Leitune, Fabrcio Mezzomo Collares,Susana Maria Werner Samuel, Fabiana Soares Grecca,

Jos Antnio Poli de Figueiredo* and Regis Burmeister dos Santos

Department of Conservative Dentistry, School of Dentistry,Federal University of Rio Grande do Sul (UFRGS),Av. Ramiro Barcelos, 2492, CEP 90035-003, Porto Alegre, RS, Brazil

*Clinical Department, School of Dentistry, Pontifcia Universidade Catlica (PUC),Av. Ipiranga, 6681, CEP 90619-900, Porto Alegre, RS, Brazil

Received 20 May, 2011/Accepted or publication 12 August, 2011

Abstract

The present study evaluated the inuence o 2% chlorhexidine and 2.5% sodium

hypochlorite on the resin sealer/dentin interace bond strength o AH Plus/gutta-perchaand Epiphany/Resilon. Seventy-two extracted bovine incisors were randomly distributedinto 6 groups according to irrigant and sealers: GS+AH=physiologic saline solution+AHPlus/gutta-percha; GS+Ep=physiologic saline solution+Epiphany/Resilon; GH+AH=2.5%sodium hypochlorite (NaOCl)+AH Plus/gutta-percha; GH+Ep=2.5% NaOCl+Epiphany/Resilon; GC+AH=2% chlorhexidine (CHX)+AH Plus/gutta-percha; and GC+Ep=2% CHX+Epiphany/Resilon. Ater 7 days at 377C and 100% humidity, the roots were cuttransversally on the long axis o the tooth in 0.8 mm (0.09)-thick slices; these sliceswere then subjected to the push-out test. Data were analyzed using a 2-way ANOVA andTukey tests at 5% signicance. The AH Plus/gutta-percha groups showed signicantlyhigher bond strength than the Epiphany/Resilon groups, regardless o the irrigant used(p

7/30/2019 _pdf321

2/7

2

development o resin-based sealers. AH Plus(De Trey-Dentsply, Konstanz, Germany) is a

two-component sealer based on an epoxyresin; it is used in combination with gutta-percha points. Epiphany SE sel-etch (PentronClinical Technologies, Wallingord, CT, USA)is a dual-curable sel-etching methacrylate resinsealer that is used in association with Resilonpoints (Resilon Research LLC, Madison, CT,USA), a thermoplastic synthetic polyesterpolymer-based material that replaces gutta-percha. A related advantage o the Epiphanysystem could be its ability to seal the canal,creating a monoblock between the sealer andpoint materials1013).

Nevertheless, chemical irrigants used duringroot canal preparation may alter the chemical

composition o the dentin surace as well asthe interaction between the dentin and resin-based sealer. The use o sodium hypochlorite,despite its disinective properties19), could afectpenetration o the resin sealer in dentin andits polymerization11,18). Furthermore, sodiumhypochlorite is a deproteinizing agent that candegenerate dentin by collagen dissolution9).

The use o chlorhexidine (CHX) as anendodontic irrigant has been proposed, pre-senting an efective antimicrobial potentialthat can produce similar results to sodiumhypochlorite3,5). However, its efects in radicular

Rocha AWet al.

72 Bovine incisor roots

Root Length = 15 mm

Endodontic TreatmentStep-back technique

ChlorhexidineSodium Hypochlorite

AH Plus

n=12

Epiphany

n=12

AH Plus

n=12

Epiphany

n=12

Sections 0.7 mm

of thickness

7 days storage

Push-out test

1 mm/min

Fig. 1 Flow chart o procedures

7/30/2019 _pdf321

3/7

3Endodontic Irrigants and Bond Strength

dentin and, consequently, in the bond strengtho resin sealers, are unclear. The purposeo this study was to evaluate the inuenceo 2% chlorhexidine and 2.5% sodium hypo-

chlorite on the resin sealer/dentin interacebond strength o AH Plus/gutta-percha andEpiphany/Resilon.

Materials and Methods

1. Specimen preparation

This study was approved by the UniversityCommittee on Ethics (protocol no.18.986).Seventy-two extracted central bovine incisors

were selected or this study. Immediately aterextraction, the teeth were stored in distilled

water at 47C or no more than 4 months.Inclusion criteria o the roots were as ollows:canals up to 3 mm in cervical diameter and atleast 15 mm in root length. External debriswas removed using a scalpel blade. The crownsurace o each tooth was sectioned belowthe cement-enamel junction perpendicular tothe long axis o the tooth with a slow speedsaw under water irrigation. The length o theroots was standardized to 15 mm. Proceduresare described in Fig. 1.

2. Endodontic treatment

The root canals were prepared with K-les(Mailleer, Ballaigues, Swiss) using the step-back preparation technique. All the roots had

15 mm o working length; a master apical le,sizes #45 and #80, was used. The roots werethen randomly divided into 6 groups o 12roots each according to the diferent irrigantsand sealers used (Table 1). The root canals

were irrigated using a syringe and a 27-gaugeneedle with 1 ml irrigant between each le.EDTA was let in the canals or 3 min and thenremoved using the same irrigant used in theirrigation.

The root canals were then dried with paper

points and obturated with the correspondentsealer o each group. The sealers weremanipulated according to the manuacturersprotocol, but the lling methods were stan-dardized using two techniques: cold lateralcompaction and vertical compaction; theexcess was seared of with a hot instrument.Ater Epiphany/Resilon obturation, each rootwas photocured (Smartlite PS, De Trey-Dentsply, Konstanz, Germany) or 40 sec at adistance o 5 mm rom the cervical surace

with irradiance o 600 mW/cm2.

Table 1 Experimental groups: Irrigation and obturation type

Groups Irrigation Obturation

GS+AH Physiologic saline solution AH Plus/gutta-percha

(Pexon, Viamo, RS) (De Trey-Dentsply, Konstanz, Germany)GS+Ep Physiologic saline solution Epiphany/Resilon

(Pexon, Viamo, RS) (Pentron Clinical Technologies, Wallingord, CT, USA)

GH+AH 2.5% NaOCl+17% EDTA AH Plus/gutta-percha(Iodontosul, POA, RS; Biodinmica Quim. (De Trey-Dentsply, Konstanz, Germany)Farm. LTDA, Ibipor, PR)

GH+Ep 2.5% NaOCl+17% EDTA Epiphany/Resilon(Iodontosul, POA, RS; Biodinmica Quim. (Pentron Clinical Technologies, Wallingord, CT, USA)Farm. LTDA, Ibipor, PR)

GC+AH 2% gel CHX+17% EDTA AH Plus/gutta-percha(Extrato Puro, POA, RS; Biodinmica Quim. (De Trey-Dentsply, Konstanz, Germany)Farm. LTDA, Ibipor, PR)

GC+Ep 2% gel CHX+17% EDTA Epiphany/Resilon(Extrato Puro, POA, RS; Biodinmica Quim. (Pentron Clinical Technologies, Wallingord, CT, USA)Farm. LTDA, Ibipor, PR)

7/30/2019 _pdf321

4/7

4

3. Push-out test

The teeth rom all the groups were storedat 377C and 100% humidity or 7 days in orderto allow the sealers to set16). Aterwards, the

roots were sectioned on the long axis using aprecision cutting machine (Isomet, BuehlerLtd., Lake Bluf, IL, USA) under constant

water coolant. Each root was sectioned intoapproximately 9 slices. The 2 mm portiono the apex was discarded due to the smalldiameter o the canal. Slices measured 0.8 mm(0.09) in thickness, and the cervical andapical diameters were measured using a digitalcaliper.

The slices were stored in bottles lled with

1.5 ml distilled water or 2 days. Aterwards,each section was marked on its apical side andpositioned on a base with a central hole in auniversal testing machine (DL2000, EMIC,So Jos dos Pinhais, PR, Brazil).

The push-out test was perormed by apply-ing a compressive load to the apical side oeach slice using a cylindrical plunger attachedto the upper portion o the testing machine

with a crosshead speed o 1 mm/min. Theload upon ailure was recorded in Newtons(N) and divided by the bond area (mm2) toexpress the bond strength in megapascals

(MPa). The total bonding area or each slicewas calculated using the ormula: (R+r)[(h2+(R1r)2]0.5, where R represents thecoronal radius, r is the apical radius, and h is

the thickness o the slice8)

.Data were analyzed using a two-way ANOVA(irrigant and sealer and sealer and depth)and post hoc tests using the Tukey multiplecomparison test at a signicance level o 5%.

Results

Push-out bond strength means (in MPa) andstandard deviations are shown in Table 2. AH

Plus/gutta-percha groups showed signicantlyhigher bond strength than the Epiphany/Resilon groups, regardless o the irrigatingsubstance used (p

7/30/2019 _pdf321

5/7

5

were signicantly lower than the cervical third(p0.05).

Mean values ollowed by diferent capitalletters in the same line indicate statisticallysignicant diferences. Mean values ollowedby diferent small letters in the same columnindicate statistically signicant diferences(p

7/30/2019 _pdf321

6/7

6

When the Epiphany group was irrigatedwith the physiologic solution, the bondstrength mean was signicantly lower thanthat o the groups that were irrigated withboth NaOCl and CHX. This correlates withthe presence o EDTA in the nal irrigationo the test groups. The nal irrigation withEDTA could promote a more avorablehybridization; thus, the test groups couldbetter support the stress o polymerization,leading to ewer adhesive ailures.

In this study, CHX did not adversely afectthe bond strength o the AH Plus andEpiphany sealers to the radicular dentin.

However, we believe that its inuence on bondstrength should be evaluated in long-termexperiments in the uture. Chlorhexidine hasthe potential to inhibit matrix metallopro-teinases, a group o enzymes that regulatethe physiologic and pathologic metabolismo collagen-based tissues, in addition to itsadsorption properties in dentinal tubules.Based on restorative dentistry studies, CHXhas been shown to be benecial to thelongevity o resin restorations615). Thereore,

CHXs efects on radicular dentin when usingresin sealers must be studied over a long-termperiod.

Conclusion

Within the methodology o this study, 2%CHX irrigation did not inuence sealer bondstrength, while 2.5% NaOCl solution inu-enced epoxy-based sealer bond strength.

Acknowledgements

The authors deny any conicts o interest.The authors are grateul to the Biochemistryand Microbiology Laboratory o the Facultyo Dentistry o the Federal University oRio Grande do Sul, the Dental MaterialsLaboratory o the Faculty o Dentistry o theFederal University o Pelotas, and PROPESQ/

UFRGS or their nancial support. Theauthors grateully acknowledge CAPES or

the scholarship o Vicente Leitune.

Reerences

1) Ari H, Yasar E, Belli S (2003) Efects o NaOClon bond strengths o resin cements to rootcanal dentin. J Endod 29:248251.

2) Carrilho MRO, Geraldeli S, Tay F, de Goes MF,Carvalho RM, Tjderhane L, Reis AF, HeblingJ, Mazzoni A, Breschi L, Pashley D (2007)In vivo preservation o the hybrid layer bychlorhexidine. J Dent Res 86:529533.

3) DArcangelo C, DAmario M, Angelis F,Zazzeroni S, Vadini M, Caputi S (2007) Efecto application technique o luting agent onthe retention o three types o ber-reinorcedpost systems. J Endod 33:13781382.

4) Erdemir A, Ari H, Gngnes H, Belli S (2004)Efect o medications or root canal treatmenton bonding to root canal dentin. J Endod 30:113116.

5) Jeansonne MJ, White RR (1994) A comparisono 2.0% chlorhexidine gluconate and 5.25%sodium hypochlorite as antimicrobial endo-dontic irrigants. J Endod 20:276278.

6) Leitune VCB, Collares FM, Samuel SMW

(2010) Inuence o chlorhexidine applicationat longitudinal push-out bond strength o berposts. Oral Surg Oral Med Oral Pathol OralRadiol Endod 110:e77e81.

7) Mohammadi Z, Abbott PV (2009) The pro-perties and applications o chlorhexidine inendodontics. Int Endod J 42:288302.

8) Nunes VH, Silva RG, Alredo E, Sousa-NetoMD, Silva-Sousa YTC (2008) Adhesion oEpiphany and AH Plus sealers to human rootdentin treated with diferent solutions. BrazDent J 19:4650.

9) Ozturk B, zer F (2004) Efect o NaOCl on

bond strengths o bonding agents to pulpchamber lateral walls. J Endod 30:362365.10) Resende LM, Rached-Jr FJ, Versiani MA,

Souza-Gabriel AE, Miranda CE, Silva-SouzaYT, Sousa Neto MD (2009) A comparativestudy o physicochemical properties o AHPlus, Epiphany, and Epiphany SE root canalsealers. Int Endod J 42:785793.

11) Shipper G, Orstavik D, Teixeira FB, Trope M(2004) An evaluation o microbial leakagein roots lled with a thermoplastic syntheticpolymer-based root canal lling material(Resilon). J Endod 30:342347.

12) Shokouhinejad N, Sharian MR, Jaari M,Sabeti MA (2010) Push-out bond strength oResilon/Epiphany sel-etch and gutta-percha/

Rocha AWet al.

7/30/2019 _pdf321

7/7

7

AH26 ater diferent irrigation protocols. OralSurg Oral Med Oral Pathol Oral Radiol Endod110:e88e92.

13) Sousa-Neto MD, Rached Junior FA, Silva RG,

Pcora JD, Silva-Sousa YTC (2008) Avaliaoda adesividade dentina do cimento AH Pluse Epiphany associados aos cones de Resilon eguta-percha. Robrac 17:2231. (in Portuguese)

14) Souza SFC, Bombana AC, Francci C, GonalvesF, Castellan C, Braga RR (2009) Polymerizationstress, ow and dentine bond strength o tworesin-based root canal sealers. Int Endod J42:867873.

15) Stratton RK, Apicella MJ, Mines P (2006) Auid ltration comparison o gutta-perchaversus Resilon, a new sot resin endodonticobturation system. J Endod 32:642645.

16) Tay FR, Loushine RJ, Weller RN, KimbroughWF, Pashley DH, Mak YF, Lai CN, Raina R,Williams MC (2005) Ultrastructural evalua-tion o the apical seal in roots lled witha polycaprolactone-based root canal llingmaterial. J Endod 31:514519.

17) Teixeira FB, Teixeira ECN, Thompson JY,Trope M (2004) Fracture resistance o endo-

dontically treated roots using a new type oresin lling material. J Am Dent Assoc 135:646652.

18) Torneck CD, Titley KC, Smith DC, Adibar A

(1990) The inuence o time o hydrogenperoxide exposure on the adhesion o com-posite resin to bleached bovine enamel. JEndod 16:123128.

19) Zicari F, Couthino E, Munck JD, Poitevin A,Scotti R, Naert I, Van Meerbeek B (2008)Bonding efectiveness and sealing ability ober-post bonding. Dent Mater 24:967977.

Reprint requests to:Dr. Fabiana Soares GreccaDepartment o Conservative Dentistry,

School o Dentistry,Federal University o Rio Grande do Sul(UFRGS),Avenida Ramiro Barcelos, 2492,CEP 90035-003, Porto Alegre, RS, BrazilTel/Fax: +55-51-3308-5191E-mail: abiana.grecca@urgs.br

Endodontic Irrigants and Bond Strength