Nanoleakage of fiber posts luted with different adhesive strategies and the effect of chlorhexidine on the interface of dentin and self-adhesive cements.

The aim of this in vitro study was to evaluate the nanoleakage of fiber posts luted using different adhesive strategies and to investigate the effect of 2% chlorhexidine (CHX) on nanoleakage at the resin-dentin interfaces of self-adhesive cements. The self-adhesive and etch-and-rinse adhesive groups tested demonstrated similar results with regard to nanoleakage. Pretreatment with CHX promoted an adequate seal at the resin-dentin interface for self-adhesive cements.

Effect of a plant-based hemostatic agent on microleakage of self-etching adhesives.

OBJECTIVE: This in vitro study evaluated the effect of Ankaferd Blood Stopper (ABS) contamination on the microleakage of one-step and two-step self-etching adhesives. STUDY DESIGN: Class V cavities were prepared at the cemento-enamel junction on both buccal and lingual surfaces of 60 freshly extracted human molars. Teeth were randomly assigned into three groups according to contamination material applied (Group I, no contamination; Group II, blood contamination; Group III, ABS contamination). In contaminated groups, one drop of blood and ABS solution was applied directly to the dentin surface and air-dried. Each group was further divided into two subgroups according to bonding agent used [Group A, Clearfil SE Bond (two-step self-etching adhesive); Group B, Adper Easy One (one-step self-etching adhesive)]. Adhesive materials were applied according to the manufacturers' recommendations. The specimens were restored using a universal microhybrid composite (Arabesk). After thermocycling (5000x, 5°C - 55°C) and immersion in a 0.5% basic fuchsin, dye penetration was evaluated under a stereomicroscope. Statistical analysis was performed with Kruskal-Wallis and Mann-Whitney U tests at p < 0.05. RESULTS: Significantly higher microleakage scores were observed when one-step self-etching adhesive was applied to blood- and ABS-contaminated dentin. However, when a two-step self etching adhesive was used, microleakage was observed only following blood contamination, not following ABS contamination. CONCLUSIONS: Although, blood contamination before adhesive application resulted in increased microleakage with both one-step and two-step self-etching adhesive systems, ABS contamination did not affect microleakage when a two-step self-ething adhesive system was used.

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive.

OBJECTIVES: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. STUDY DESIGN: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhesive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. RESULTS: A statistically significant difference was observed in microleakage between the two groups (P<0.001). CONCLUSIONS: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage.

An in vitro evaluation of radicular penetration of hydrogen peroxide from bleaching agents during intra-coronal tooth bleaching with an insight of biologic response.

OBJECTIVES: External root resorption is the complication of intra-coronal bleaching done with 30% H2O2 alone or mixed with sodium perborate but not with sodium perborate mixed with water. The study was done to comparatively evaluate the H2O2 leakage from three H2O2 liberating bleaching agents. STUDY DESIGN: Fifty one single rooted human teeth were used. After root canal therapy gutta percha was removed below cemento-enamel junction. Three bleaching agents: sodium perborate mixed with water, sodium perborate mixed with 30% H2O2 and 30% H2O2 alone were used. Teeth without defect, with cervical root defect and with mid root defect constituted group A, group B and group C. According to various bleaching agents groups were subdivided into subgroup 1, 2 and 3. H2O2 leakage was measured with the help of spectrophotometer RESULTS: Almost all teeth showed H2O2 leakage. It was maximum in B1 followed by C1, B2, A1, A2, C2, B3, A3 and C3. CONCLUSION: Sodium perborate mixed with water was found to be the best bleaching agent.

[Effect of carbamide peroxide bleaching agents on micro-leakage of composite resin interface in vitro].

OBJECTIVE: To evaluate the effect of carbamide peroxide (CP) bleaching agents at different concentrations and with different carriers on the micro-leakage of composite resin interface. METHODS: Class V cavity (2 mm in diameter and 2 mm in depth) preparations were made at the enamelo-cemental junction on the buccal and lingual surfaces of 35 extracted human premolars. The cavities were filled with hybrid composite resin. The teeth were stored for 24 h in distilled water at 37 degrees celsius; before thermocyling for 500 times between 5 and 55 degrees celsius;. The teeth were then randomly assigned into 7 groups, and in groups 1-6, the bleaching gels containing 10% or 20% of CP were applied on the buccal and lingual surface of the teeth for two weeks (6-8 h/day, 37 degrees celsius;, 100% relative humidity) using Carbopol, PVP or Poloxamer as the thickening carriers, respectively. The seventh group served as the control without bleaching treatment. Nail polish was applied to the surface of the tooth, and all the teeth were immersed in ammoniacal silver nitrate solution followed by developing solution. The teeth were finally sectioned through the midline of the restoration and observed under stereomicroscope. SEM micrographs were also made to observe the interface. RESULTS: With the same bleaching agent, the micro-leakage in the gingival wall was slightly greater than in the occlusive wall, but the difference was not significant. Only 20% CP with Poloxamer as the thickening agent significantly increased the leakage of dentine-resin composite interface, and 10% and 20% CP with Carbopol or PVP as the thickening agents and 10% CP with Poloxamer produced minimal effects on filling the micro-leakage. CONCLUSION: Thickening carriers and the concentration of CP (20% or below) have no significant effect on micro-leakage of composite resin.

[Restorations with composite resin and hybrid materials clinical]. / Restaurarile cu rasini compozite si materiale hibride. Studiu clinic în cavitati de clasa A II-A.

UNLABELLED: The aim of this study was to analyze the in vivo interface biomaterials--dental hard structures associated techniques applied in the cavities of class II after 3 years. MATERIAL AND METHOD: The study was longitudinal clinical type. They restored a total of 90 teeth of class II. Cavity preparation was done by mechanical treatment. Cavity preparation was done by mechanical treatment. Filling cavities was performed using as a substitute enamel composite resin (CR) Filtek Supreme (3MESPE) giomer (G) Beautiful (Shofu) and as a substitute dentinar resin modified glass ionomer (RMGI) Vitremer (3MESPE) and compomer flow (C flow) Dyract Flow (Dentsply De Trey) restorations were divided into 4 groups depending on materials used. Group 1--CR-RMGI-24 restoration, Group 2--G-RMGI 23-restoration, Group 3--G-Cflow 21-restoration, Group 4--CR-C flow 22-restoration. Evaluation was done with restorations: modified Rydge criteria. Statistical data processing was performed with SPSS 10.00, 13.00 setting a threshold of p = 0.05 signified statistical. RESULTS: Analysis of color criteria that there are significant differences in terms of 24 months for restorations made with composite resin for p = 0.05 (R = 0.368). The 12-month evaluation of marginal coloration was in favor of the restorations made with resin composite Filtek Supreme (3MESPE) score A in 95.65% (44) p = 0037. CONCLUSION: Restorations success depends largely on the nature of the material, the dental composition adjacent wall restoration and by possibility can prevent marginal leakage.

Effect of calcium hydroxide dressing on microleakage of compositerestorations in endodontically treated teeth subsequent to bleaching

Objective: This study evaluates the effect of calcium hydroxide dressing on microleakage of composite restorationsfollowing non-vital bleaching. Methods: A total of 45 sound extracted human maxillary central incisorsunderwent endodontic treatment. The teeth were randomly divided into three groups (n=15). In group 1, accesscavities were restored with composite. In group 2, the teeth underwent a bleaching procedure for one week beforebeing restored with composite. In group 3, following a bleaching procedure, calcium hydroxide paste was placedin the pulp chamber for one week. The teeth were then restored with composite. The specimens were subjected toa dye leakage test. The data was analyzed using Kruskal-Wallis and Mann-Whitney U tests. Results: There weresignificant differences between the groups (P<0.0005). No statistically significant differences were found betweengroups 2 and 3, while the differences between other groups were significant. Conclusions: The bleaching agentincreased microleakage of composite restorations in non-vital bleaching, whereas microleakage was not found tobe increased by calcium hydroxide (AU)

Effect of calcium hydroxide dressing on microleakage of composite restorations in endodontically treated teeth subsequent to bleaching.

OBJECTIVE: This study evaluates the effect of calcium hydroxide dressing on microleakage of composite restorations following non-vital bleaching. METHODS: A total of 45 sound extracted human maxillary central incisors underwent endodontic treatment. The teeth were randomly divided into three groups (n=15). In group 1, access cavities were restored with composite. In group 2, the teeth underwent a bleaching procedure for one week before being restored with composite. In group 3, following a bleaching procedure, calcium hydroxide paste was placed in the pulp chamber for one week. The teeth were then restored with composite. The specimens were subjected to a dye leakage test. The data was analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: There were significant differences between the groups (P<0.0005). No statistically significant differences were found between groups 2 and 3, while the differences between other groups were significant. CONCLUSIONS: The bleaching agent increased microleakage of composite restorations in non-vital bleaching, whereas microleakage was not found to be increased by calcium hydroxide.

Effect of postoperative bleaching on marginal leakage of resin composite and resin-modified glass ionomer restorations at different delayed periods of exposure to carbamide peroxide.

AIM: To evaluate the effect of dental bleaching with carbamide peroxide at different exposure times on the microleakage of resin composite and resin-modified glass ionomer restorations after placement in extracted human teeth. METHODS AND MATERIALS: 120 Class V cavity preparations were placed at the cementoenamel junction (CEJ) of human teeth. Half of the cavities were restored with Filtek P60 resin composite (C) and the other half were restored with Fuji II LC resin-modified glass ionomer (G). Each group was randomly divided into four subgroups (n=15). Groups C1 and G1 were not bleached and stored in artificial saliva at 37 degrees C to serve as control groups, while in Groups C2 and G2, C3 and G3, and C4 and G4 specimens were exposed to a 15% carbamide peroxide gel for one day, one week, and two weeks, respectively, following the placement of restorations. Microleakage was assessed using the dye penetration method. Data were analyzed using the Kruskal-Wallis and Wilcoxon tests (p=0.05). RESULTS: The Kruskal-Wallis test showed no significant difference among all groups of composite or glass ionomer restorations with either enamel or dentinal margins with regard to microleakage (p>0.05). The Wilcoxon test revealed more marginal leakage in the enamel/glass ionomer margins than the enamel/composite margins (p<0.05). In comparisons within each group, the Wilcoxon test showed there was more microleakage in dentinal margins of composite restorations than in the enamel margins in the test groups (p<0.05). The dentinal margins of the glass ionomer in control groups showed more leakage than the enamel margins, but after the bleaching procedure all experimental groups showed statistically similar microleakage in both the enamel and dentinal margins (p>0.05). CONCLUSION: Postoperative bleaching with carbamide peroxide could increase microleakage in the dentinal margins of composite and the enamel margins of resin-modified glass ionomer restorations. CLINICAL SIGNIFICANCE: Rebonding of resin composite restorations should be considered following bleaching with 15% carbamide peroxide in order to reseal the margins. Resin-modified glass ionomer is not suitable as a filling material before bleaching because of its susceptibility to increased microleakage.

Effect of vital tooth bleaching on solubility and roughness of dental cements.

STATEMENT OF PROBLEM: Vital tooth bleaching may affect properties of dental cements used for fixed prostheses. PURPOSE: The purpose of this study was to examine the effect of a combined in-office and at-home bleaching regimen on changes in surface roughness and depth loss of a variety of commercially available dental cements. MATERIAL AND METHODS: Five cement classifications were tested: glass ionomer, resin-modified glass ionomer, resin,self-adhesive resin cement, and zinc phosphate. Cements were placed in multiple wells in plastic blocks. After setting,the surface profile of each block was determined, and average roughness and vertical height of cement surface from the specimen holder were recorded. Blocks were water stored (control) or subjected to in-office and at-home bleaching(n=12). Surfaces were rescanned and pre- and posttest parameter changes were calculated. Statistical analysis consisted of Mann-Whitney-Wilcoxon Rank Sum and Student t tests applied to control and bleaching parameterc hanges within the same cements. A family-wise alpha of .05 was maintained by using a Bonferroni-adjusted level of significance preset to .01 per test. RESULTS: Zinc phosphate showed the only significant depth increase (P=.004) from bleaching: 0.9 +/- 0.7 microm deeper than the water-control group. Only resin-modified glass ionomer showed a significant (P=.004) increase in roughness from bleaching; values increased by 0.05 +/- 0.03 microm over the water-control group. CONCLUSIONS: In-office and at-home bleaching significantly increased depth loss of zinc phosphate and increased resinmodified glass ionomer roughness. However, the absolute values of differences observed, as compared to the wateronly control, were considered to be clinically insignificant. (J Prosthet Dent 2009;102:148-154)

In vitro evaluation of giomers microleakage after exposure to 33% hydrogen peroxide: self-etch vs total-etch adhesives.

This study evaluated the microleakage of a giomer resin bonded with total-etch and self-etch adhesive systems after exposure to hydrogen peroxide. Thirty freshly extracted, caries-free human premolars and molars were used. The teeth were randomly divided into two groups: Group I was exposed to 33% hydrogen peroxide (Niveous-Shofu) for 30 minutes daily for five consecutive days; Group II received no treatment (control). A week later, Class V standardized preparations were performed on the facial and lingual surfaces, with the gingival margin placed 1 mm below the CEJ. Each group was then divided into two subgroups: in Groups IA and IIA, a self-etching adhesive system (FL Bond-Shofu) was applied, and in Groups IB and IIB, a total-etch adhesive system (Prime Bond NT-Dentsply/Caulk) was applied according to manufacturers' instructions. The teeth were restored using 2-mm increments of Beautifil A2 resin-based giomer material (Shofu). Each layer was cured using a Spectrum 800 curing light (Dentsply/Caulk) for 20 seconds at 600mW/cm2. The teeth were thermocycled 500x between 5 degrees C and 55 degrees C with a dwell of 30 seconds; they were then placed in a 0.5% methylene blue dye solution for 24 hours at 37 degrees C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margin under a stereomicroscope at 20x magnification. Dye penetration was scored using the following scoring system 0 = no penetration; 1 = partial dye penetration along the occlusal or gingival wall; 2 = partial dye penetration along the occlusal or gingival wall but did not include the axial wall; 3 = dye penetration to and along the axial wall. A Mann-Whitney test revealed a statistically significant difference between subgroups at the occlusal level (p < 0.0001). Group IA yielded the most microleakage. No statistically significant difference was reported at the gingival level. Microleakage was affected by hydrogen peroxide exposure only at the enamel cavosurface margin when a self-etching primer adhesive system was used.

Ultrastructure of intraradicular dentin after irrigation with BioPure MTAD. II. The consequence of obturation with an epoxy resin-based sealer.

In addition to an initial report on the creation of thick demineralized collagen matrices in root dentin that were irrigated with BioPure MTAD or EDTA as final rinses for 5 minutes, this study examined the effect of a 2-minute irrigation time of these final irrigants on the extent of demineralization of intact intraradicular dentin and on interfacial nanoleakage after obturation with AH Plus and gutta-percha using warm vertical compaction. Transmission electron microscopy confirmed that the reduction in irrigation time did not compromise the smear layer removing capacity of these two irrigants when 1.3% NaOCl was employed as the initial rinse. BioPure MTAD created 5 to 6 microm thick demineralized dentin matrices, while 17% EDTA produced 1 to 2 microm thick matrices that were suboptimally infiltrated by the epoxy resin-based sealer, as manifested by the occurrence of silver tracer deposits within the hybrid layers.

Effect of non-vital tooth bleaching on microleakage of coronal access restorations.

This study evaluated the effect of non-vital tooth bleaching on microleakage of composite resin/bovine tooth interface at different post-bleaching times. A total of 320 teeth were cleaned. A pulp chamber access cavity was made at the lingual surface of each tooth. The teeth were randomly divided into four groups: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP-37% carbamide peroxide; and CON-distilled water (control). The bleaching agents were replaced every 7 days, over 4 weeks. Following bleaching procedures, the groups were divided into four subgroups (n = 20), according to the post-bleaching times: 0 (baseline), 7, 14 and 21 days. After that, the cavities were restored with an adhesive system (Single Bond; 3M Co., St Paul, MN, USA) and a composite resin (Z100/3M). The specimens were thermocycled, stained with 2% methylene blue solution (pH 7), and sectioned longitudinally. The teeth were evaluated blind and independently by three previously calibrated examiners, to provide representative scores. The data were submitted to Kruskal-Wallis and multiple comparison tests (alpha=0.05). At baseline and 7 days, the SPH group showed a higher degree of dye penetration than the CON (P=0.04). At 14 and 21 days, there were no differences among groups. The association of sodium perborate with 30% hydrogen peroxide or with water may affect the sealing ability of composite resin restorations performed up to 7 days after bleaching procedures.

Microinfiltração em restaurações ocluso-proximais de dentes deciduos em diferentes materiais restauradores / Microleakage in occluso-approximal restorations in primary teeth in function of different restorative materials

O objetivo deste estudo in vitro foi de comparar a microinfiltração em cavidades ocluso-proximais de molares decíduos restaurados com três diferentes materiaisrestauradores. Foram utilizados 15 molares decíduos, onde foram confeccionados preparos cavitários do tiposlot vertical nas faces mesial e distal. No Grupo 1 (n=10), as restaurações foram realizadas com a resina composta híbrida Z-100 (3M). No Grupo 2 (n=10) utilizou-se o cimento de ionômero de vidro modificado por resina Vitremer (3M). No Grupo 3 (n=10) as restaurações foram realizadas com a resina modificada por poliácidos Dyract (Dentsply). Todas as restaurações foram realizadas seguindo-se as recomendaçoes dos fabricantes. Os espécimes foram termociclados, impermeabilizados e imersos em corante. Após, foram confeccionados e avaliados quanto à microinfiltração. Os resultados demonstraram níveis variados de microinfiltração entre os diferentes materiais restauradores. Os dados foram tratados estatisticamente (Teste de Kruskal-Wallis, P<0,001) que demonstrou que a resina composta híbrida e o cimento de ionõmero de vidro modificado por resina apresentaram níveis de microinfiltração significantemente maiores do que a resina composta modificada por poliácidos. Conclui-se que a resina composta modificada por poliácidos apresentou o melhor desempenho quanto à microinfiltração

Interferência da camada residual no selamento apical / Smear layer interference on the apical seal

Para muitos autores, a obturaçäo constitui a etapa mais importante da terapia endodôntica, haja visto que, mesmo diante de eventuais falhas no preparo do canal que permitissem a permanência de microorganismos no seu interior, pela obturaçäo correta, o tratamento teria êxito. Para isso, ela deveria promover um vedamento hermético, pois dessa forma, aqueles microorganismos ficariam enclausurados. Sabe-se, entretanto, que após o preparo, forma-se uma camada residual sobre as paredes do canal, o que dificultaria a ocorrência desse vedamento. Através da infiltraçäo apical de corante, observada em dois momentos diferentes, esse trabalho visa analisar se a presença da camada residual interfere na qualidade da obturaçäo. Os resultados mostram que sim

Avaliaçäo in vitro da microinfiltraçäo marginal de restauraçöes realizadas com um cimento de ionômero de vidro modificado por resina e uma resina composta modificada por poliácidos associadas a dois sistemas adesivos / Microleakage in vitro evaluation of resin-modified glass ionomer cement and polyacid-modified resin composite restorations in association with two dentin adhesive systems

Avaliou-se in vitro a microinfiltraçäo marginal de restauraçöes realizadas com um cimento de ionômero de vidro modificado por resina (Vitremer/3M) e uma resina composta modificada por poliácidos (Dyract/Dentsply) associadas a dois sistemas adesivos (All Bond 2/Bisco e One Step/Bisco). Cavidades classe II modificadas foram preparadas nas superfícies M e D de 40 pré-molares hígidos, tendo a parede gengival estendida a 1mm abaixo da junçäo cemento-esmalte. Os espécimes foram divididos em 4 grupos de 20 restauraçöes cada, sendo: 1) composto do sistema adesivo One Step + Dyract; 2) composto pelo One Step + Vitremer; 3) apresentava o sistema adesivo All Bond 2 + Dyract; 4) All Bond 2 + Vitremer. Após o término das restauraçöes, os espécimes foram submetidos à termociclagem nas temperaturas de 5ºC e 55ºC, totalizando 500 ciclos. Em seguida, foram submersos em soluçäo de fucsina básica a 0,5 por cento em 37ºC por 24 horas. Os dentes foram seccionados e a microinfiltraçäo marginal na interface dente/restauraçäo foi avaliada ao longo da parede gengival, através de medida linear em micrômetros. Os resultados deste estudo demonstraram que nenhum dos materiais testados foi capaz de eliminar completamente a microinfiltraçäo marginal, onde a associaçäo dos sistemas adesivos aos materiais restauradores utilizados näo influenciou de maneira significativa a capacidade de selamento das restauraçöes avaliadas. O Vitremer mostrou ter capacidade de selamento superior quando comparado ao Dyract em relaçäo à microinfiltraçäo marginal

Avaliaçäo da microinfiltraçäo e da açäo anticariogênica em restauraçöes com resina composta associadas a outros materiais / Evaluation of microleakage and of anticariogenic action in restorations with composite resin associated to others materials

Este estudo in vitro avaliou a microinfiltraçäo e açäo anticariogênica nas restauraçöes com sistema adesivo/resina composta (Glacier) e nas associaçöes compômeros (Freedom, F2000, Dyract) ou ionômero modificado por resina (Vitremer)/resina composta em cavidades classe II amplas (MOD) com margem cervical 1mm abaixo ou acima da junçäo amelo-cementária. Foram realizados 100 preparos em premolares e molares extraídos submetidos ao condicionamento prévio do esmalte e dentina, com exceçäo do grupo Vitremer, e restaurados com a utilizaçäo dos diferentes sistemas adesivos de acordo com as orientaçöes dos fabricantes. Foi utilizada uma matriz metálica e os compômeros ou cimento de ionômero de vidro modificado por resina foram inseridos nas margens cervicais das caixas proximais até a parede pulpar e em seguida polimerizados em várias direçöes. Os materiais foram desgastados mantendo uma espessura de 2,0mm. As restauraçöes foram completadas com a utilizaçäo dos sitemas adesivos/resina composta (técnica mista). A avaliaçäo da área infiltrada dos dentes seccionados após ciclagem mecânica, foi realizada através da penetraçäo do corante (fucsina a 0,5 por cento). Os resultados demonstraram que os dentes resturados com associaçäo Vitremer/resina apresentaram menores áreas infiltradas nas margens cavitárias em dentina e esmalte em comparaçäo com as demais associaçöes de materiais utilizadas...

Influência do hidróxido de cálcio e do EDTA na marcaçäo da infiltraçäo marginal de azul de metileno em obturaçäo de canais radiculares / Influence of calcium hydroxide and EDTA in marginal infiltration of metilen blue in root canal obturation

Com o objetivo de avaliar a influência do hidróxido de cálcio e do EDTA na marcaçäo da infiltraçäo marginal de corante azul de metileno a 2 por cento em canais radiculares obturados pela técnica da condensaçäo lateral, foram empregados 188 dentes incisivos centrais superiores humanos extraídos. Após serem instrumentados e impermeabilizados, foram divididos em 3 grupos de 60 elementos cada, sendo que outros 8 dentes foram utilizados como controle. Cada grupo foi dividido em 2 subgrupos, os quais, foram subdivididos em dois, totalizando 12 subgrupos com 15 elementos cada, dessa forma descritos: Grupo I - obturaçäo imediata; em 30 dentes foi aplicado EDTA por 3 minutos antes da obturaçäo; em 30 dentes a obturaçäo foi feita sem a aplicaçäo do EDTA; 30 dentes foram obturados com cimento de óxido de zinco e eugenol e 30 obturados com pasta de hidróxido de cálcio; Grupo II - aplicaçäo de EDTA por 3 minutos e preenchimento de todos os canais com pasta de hidróxido de cálcio (curativo); em 30 dentes o EDTA foi reaplicado após a remoçäo do curativo, e nos outros 30 dentes näo; 30 dentes foram obturados com cimento de óxido de zinco e eugenol e 30 obturados com pasta de hidróxido de cálcio; Grupo III - após a instrumentaçäo, os canais foram preenchidos com pasta de hidróxido de cálcio (curativo) sem a aplicaçäo prévia do EDTA; após a remoçäo do curativo, em 30 dentes o EDTA foi aplicado e em outros 30 näo; 30 dentes foram obturados com cimento de óxido de zinco e eugenol e outros 30 com pasta de hidróxido de cálcio...