Microfiltración coronal según materiales de restauración temporal empleados en endodoncia / Coronal microleakage according to the temporary restorative materials used in endodontic treatment

RESUMEN Introducción: La microfiltración coronal causada por los materiales de restauración temporal es considerada una de las causas del fracaso de los tratamientos endodónticos. A raíz de ello, en los últimos años se ha buscado crear un material de restauración temporal que sea capaz de evitar este problema. Objetivo: Comparar in vitro la microfiltración coronal de un cemento experimental y cuatro materiales de restauración temporal usados en endodoncia. Métodos: Se realizaron cavidades clase I en 90 premolares, divididos en 10 grupos (n= 9) y evaluados en dos periodos de tiempo (1 y 2 semanas). Se realizó la elaboración del cemento experimental, posteriormente se llevó a cabo el sellado coronal de las piezas dentales con el cemento experimental, Clip F (VOCO), Eugenato (MOYCO), Ketac™ Molar Easymix 3M (ESPE) y Coltosol® F. Los especímenes fueron sumergidos en tinta china (Pelikan) durante 1 y 2 semanas. Se evaluó la microfiltración en la interfase pared dentinaria-restauración temporal utilizando un esteromicroscopio (Leica Microsystems LAS EZ versión 2.0.0). La medición se realizó en milímetros en el programa LAS EZ versión 2.0.0. Resultados: Se encontró diferencias estadísticamente significativas (p < 0,05) al comparar la microfiltración coronal de los cinco materiales de restauración temporal, según el tiempo de exposición en tinta (1 y 2 semanas). Conclusiones: El cemento experimental presentó menor microfiltración que el Coltosol® F y Ketac™ Molar EasyMix 3M (ESPE); sin embargo, ninguno de los cuatro materiales fue capaz de prevenir la microfiltración en su totalidad(AU)

ABSTRACT Introduction: Coronal microleakage caused by temporary restorative materials is viewed as one of the reasons for endodontic failure. Efforts have been made in recent years to create a temporary restorative material capable of preventing that problem. Objective: Compare in vitro coronal microleakage of an "experimental cement" and four temporary restorative materials used in endodontics. Methods: Class I cavities were made in 90 premolar teeth divided into 10 groups (n= 9) and evaluated at two time periods (1 and 2 weeks). The "experimental cement" was prepared and then coronal sealing of the teeth was performed with the experimental Cement, F (VOCO), Eugenato (MOYCO), Ketac™ Molar Easymix 3M (ESPE) and Coltosol® F. The pieces were submerged in India ink (Pelikan)for 1 and 2 weeks. Microleakage was evaluated on the interface dentin wall / temporary restoration using a stereo microscope (Leica Microsystems LAS EZ version 2.0.0). Measurement was made in millimeters using the software LAS EZ version 2.0.0. Results: Statistically significant differences were found (p < 0.05) when comparing coronal microleakage in the five temporary restorative materials according to exposure time in ink (1 and 2 weeks). Conclusions: The experimental cement had less microleakage than Coltosol® F and Ketac™ Molar EasyMix 3M (ESPE). However, none of the four materials was capable of completely preventing microleakage(AU)

Influence of Cavity Dimensions on Microleakage of Two Bulk-Fill Composite Resins

Objective: To evaluate the effect of cavity dimensions on the amount of microleakage in two different types of bulk-fill composite resins. Material and Methods: Forty class II cavities were prepared in the mesial and distal surfaces of human molars without any carious lesions. The samples were divided into 4 groups (n=10): Group 1: cavities with 3 mm of buccolingual width (known as the smaller cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 2: cavities with 6 mm of buccolingual width (larger cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 3: cavities with 3 mm of buccolingual width, filled with X-Tra Base composite resin; and Group 4: cavities with 6 mm of buccolingual width, filled with X-Tra Base composite. After the specimens were thermocycled for 500 cycles at 5/55°C, they were immersed in 1% methylene blue for 24 hours, and then cut into sections mesiodistally in the longitudinal axis of each tooth. Then, the samples were scored regarding the amount of dye penetration in two occlusal and gingival areas under a stereomicroscope (x32). Data was submitted to Kruskal- Wallis and Mann-Whitney tests. Results: The highest degrees of microleakage in larger cavities filled with X-Tra Base among the four groups. There was a significant statistic difference (p=0.012) between large and small cavities filled with X-Tra Base (Groups 3 and 4); however, there was no significant difference between the two cavity sizes of Tetric N-Ceram Bulk-filled groups. Conclusion: Microleakage of composite resins depends on the dimension of the cavity and the type of composite resin used.

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study

ABSTRACT Objective: To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Material and Methods: Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Results: Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). Conclusions: We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

Evaluation of bacterial infiltration in teeth with apical barrier of MTA: an ex-vivo study

Objective: to evaluate the ability of different MTA thicknesses (3 and 5 mm), with or without conventional fillings, in preventing bacterial infiltration of Enterococcus faecalis in teeth with incompletely formed apices. Material and Methods: apical barriers were created which 3- and 5-mm-thick of MTA with and without conventional filling of the remaining root. 48 single-rooted human teeth were divided into four experimental groups (n=10) and two controls groups (n=8). After being mounted on a testing apparatus, Enterococcus faecalis was used as an indicator of bacterial infiltration. Inoculations were renewed every 3 days during a period of 60 days, and infiltration was assessed daily by checking the culture medium for turbidity. The results were analyzed using descriptive and analytical statistics (survival analysis). The level of significance was set at 5%. The tests were performed using the software GraphPad Prism 5.00. Results: the positive control group infiltrated within 24 hours, while the negative control group, no infiltrated. The Long-rank test did not demonstrate the existence of differences between groups. However, the Long-rank test for tendencies showed of a tendency to retard the infiltration. Conclusion: none of the MTA barriers were effective in preventing bacterial infiltration. The gutta-percha filling of the root segment in association with the 5-mm apical barrier of MTA showed a tendency to delay bacterial infiltration.

Operatoria dental y endodoncia 1: la degradación de la interfaz resina-dentina favorece la filtración bacteriana / Operative dentistry and endodontics 1: the interface resin-dentin degradation allows for the bacterial microleakage

La integridad y la estabilidad de la interfase adhesivo/dentina en las restauraciones realizadas mediante resinas compuestas se encuentra constantemente comprometida por la hidrólisis progresiva de sus componentes hidrofílicos y la degradación de la matriz colágena, producida por la reactivación de una serie de endopeptidasas denominadas metaloproteinasas (MMP) y otras enzimas colagenolíticas que se encuentran fosilizadas en la matriz de la dentina. Esto lleva a la destrucción de la capa híbrida y facilita la penetración bacteriana en la interfase, el aumento de la hipersensibilidad posoperatoria y la formación de caries recurrentes. Estos problemas inciden además en la pérdida de retención de la restauración y se constituyen en el principal factor etiológico de los procesos inflamatorios que comprometen seriamente la salud de la pulpa dental. Debido a que la integridad de la matriz colágena es esencial para preservar la durabilidad de la adhesión de las restauraciones, se han intentado algunas estrategias, con el objeto de inhibir o al menos reducir en lo posible la acción de las enzimas colagenolíticas sobre la estabilidad de la interfase. A pesar de que algunas de las estrategias ensayadas hasta el momento han demostrado ser eficaces, aún se encuentran en una etapa netamente experimental y requieren ser más profundamente investigadas

Assessment of coronal leakage of a new temporary light-curing filling material in endodontically treated teeth.

Introduction: The aim of this study was to evaluate the sealing ability of a new temporary filling material X‑Temp LC (DFL, São Paulo, SP, Brazil) compared with that obtained for Coltosol (Vigodent, Rio de Janeiro, RJ, Brazil) and Vitro Fill (DFL, Rio de Janeiro, RJ, Brazil), using a dye penetration test. Methods: Standard endodontic access cavities were prepared in 75 human premolars. The teeth were divided into five groups (n = 15 for each group), including a positive (no sealing of access cavity) and a negative control (Filtek Z350 XT, 3M, São Paulo, SP, Brazil). In the experimental groups, the access cavities were sealed with one of the three tested materials. After that, the teeth were immersed in 10% Indian ink for 14 days. The teeth were then rinsed, dried, sectioned in bucco‑lingual direction and evaluated under a stereomicroscope using scores for dye penetration. Data were analyzed using Kruskall‑Wallis and Student‑Newman‑Keuls tests (α =0.05). Results: Positive control sections exhibited complete dye penetration and negative control had no specimen showing marginal leakage. X‑Temp LC and Coltosol showed similar results, with no statistical difference between them. Vitro Fill exhibited the highest dye penetration among the experimental groups. Conclusion: The results of this in vitro study suggest that all temporary restorative materials exhibit some degree of marginal leakage. X‑Temp LC and Coltosol, however seal better than Vitro Fill glass ionomer cement.

Avaliação in vitro da infiltração marginal em copings fixados a dentes humanos com três diferentes cimentos resinosos / In vitro evaluation of marginal microleakage in copings fixed to human teeth with three different resin cements

Objetivo: Comparar, por meio do corante azul-de-metileno, a microinfiltração nas interfaces de preparos dentários e copings metálicos fixados com 3 cimentos resinosos. Método: Utilizou-se 36 pré-molares humanos, que foram preparados para coroa total metalo-cerâmica com término cervical em chanfro. Os dentes foram moldados e os troquéis encerados e incluídos em revestimento para obtenção de copings em liga à base de níquel-cromo. A amostra foi agrupada conforme o material de cimentação: Grupo I: copings fixados com adesivo Single Bond e RelyX ARC; Grupo II: copings fixados com adesivo ED Primer e cimento Panavia F; Grupo III: coping s fixados com cimento autoadesivo RelyX U 100 e Grupo IV: copings fixados com oxifosfato de zinco (controle). Os dentes foram imersos em água destilada durante 7 dias, submetidos à, ciclagem térmica e impermeabilizados externamente, exceto nas interfaces em questão. A seguir, foram imersos em solução aquosa de azul-de-metileno por 8 horas. Os copings foram cortados com discos de carborundum, removidos dos dentes e as amostras avaliadas por 3 examinadores calibrados que atribuíram graus de infiltração que variavam de 0 a 4. Resultados: A média dos escores do Grupo I foi 2,67; do II 1,22; III 0,11 e do Grupo IV 3,78. Utilizando o teste de Kruskall-Wallis verificou-se diferenças estatísticas entre os Grupos I e III; II e IV; III e IV (p menor que 0,05). Conclusão: Dentre os cimentos resinosos testados, apenas a combinação Single Bond com RelyX ARC não foi superior ao oxifosfato e que o Panavia F foi o material que apresentou maior resistência a infiltração do corante.

Objective: To compare, using methylene blue dye infiltration, the microleakage at interfaces of tooth preparations and metallic copings fixed with three resin cements. Method: Thirty-six human premolars prepared to receive a complete metal-ceramic crown with chamfer cervical margin. Impressions were obtained from the teeth and the cores were waxed and invested to obtain nickel-chromium-alloy copings. The sample was grouped according to the cementing material: Group I: copings fixed with Single Bond adhesive system and RelyX ARC cement; Group II: copings fixed with ED Primer adhesive system and Panavia F cement; Group III: copings fixed with RelyX U 100 self-adhesive cement; and Group IV: copings fixed with zinc oxiphosphate cement (control). The teeth were immersed in distilled water during 7 days, subjected to a thermocycling regimen, rendered waterproof on the outer surfaces, except for the interfaces to be analyzed. Then, the teeth were immersed in a methylene blue aqueous solution for 8 hours. The copings were cut with carborundum discs and removed from the teeth, and the specimens were examined by 3 calibrated examiners that attributed microleakage scores from 0 to 4. Results: The mean scores in Groups I to IV were, respectively, were 2.67, 1.22, 0.11 and 3.78. The Kruskal-Wallis test revealed statistically significant differences between Groups I and III; Groups II and IV; and Groups III and IV (p less than 0.05). Conclusion: Among the tested resin cements, only the combination of Single Bond and RelyX ARC was not superior to the zinc oxiphosphate cement, and that Panavia F was the material with highest resistance to dye penetration.

A influência da temperatura de secagem e do tempo de aplicação de adesivos autocondicionantes na microinfiltração marginal / Influence of drying temperature and application time of self-etch adhesive systems on marginal microleakage

Objetivo: Avaliar "in vitro" a eficiência de adesivos autocondicionantes na microinfiltração marginal, variando o tempo de aplicação e o mecanismo de secagem. Método: Cavidades classe II foram preparadas em 80 molares humanos hígidos, divididos em quatro grupos: G1, Adper SE Plus (ASEP); G2, All Bond SE (ABSE); G3, Go! (GO); G4, Clearfil SE Bond (CSEB). Os adesivos foram utilizados variando o tempo de aplicação (recomendado pelo fabricante e duplicado) e o mecanismo de secagem (ar frio e quente). Após restaurados, os dentes foram armazenados em água destilada por 24h, termociclados, impermeabilizados, imersos em azul de metileno 2%, seccionados e avaliados quanto ao grau de microinfiltração de forma qualitativa, com lupa estereoscópica 40X por três examinadores calibrados. Utilizou-se a técnica estatística descritiva e inferencial (testes de Mann-Whitney e Kruskal-Wallis com aplicação de comparações pareadas do referido teste). Resultados: Observaram-se diferentes níveis de infiltração entre os adesivos em relação a forma de secagem e tempo de aplicação. A menor infiltração foi do ASEP com ar frio e tempo duplicado (média 11,05) e a maior foi do ABSE com ar frio e tempo de fabricante (média 30,50). Diferença entre os adesivos só não foi estatisticamente significante na associação ar quente e tempo do fabricante (p maior que 0,05). Analisando-se a forma de secagem e o tempo de aplicação, independentemente, o ASEP mostrou menor infiltração ao aplicar ar quente (24,73) e duplicar o tempo (22,55). Conclusão: A secagem com ar quente e a duplicação do tempo de aplicação do sistema adesivo mostrou-se ferramenta útil para melhorar a qualidade do selamento marginal em sistemas adesivos à base de água.

Objective: To evaluate "in vitro" the efficiency of self-etch adhesive systems on the marginal microleakage, varying the adhesive application time and the air drying mode. Method: Class II cavities were prepared in 80 sound human molars, divided into four groups: G1, Adper SE Plus (ASEP); G2, All Bond SE (ABSE); G3, Go! (GO); G4, Clearfil SE Bond (CSEB). The adhesive systems were used varying the application time (recommended by manufacturer or doubled) and the drying mode (cold air and hot air). The restored teeth were stored in distilled water for 24 h, subjected to a thermocycling regimen, rendered waterproof, immersed in 2% methylene blue, sectioned and examined as to the level of microleakage qualitatively with a 40x stereoscopic loupe by three calibrated examiners. Descriptive and inferential statistics were used for data analysis (Mann-Whitney and Kruskal-Wallis tests with paired comparisons). Results: There were different levels of microleakage among the adhesive systems regarding the drying mode and adhesive application time. The least leakage was obtained for ASEP with cold air drying and doubled adhesive application time (mean 11.05) and the greatest was obtained for ABSE with cold air drying and manufacturer's adhesive application time (mean 30.50). Difference among the adhesive systems was not statistically significant (p greater than 0.05) only for the combinations of hot air drying and manufacturer's recommended application time. Regarding the drying mode and the application time, independently, ASEP showed less leakage when drying was done with hot air (mean 24.73) and the adhesive application time was doubled (mean 22.55). Conclusion: Drying with hot air and doubling the adhesive application time were found to be effective in increasing the quality of the marginal seal in water-based adhesive systems.

Análise in vitro da infiltração cervical bacteriana em dentes preenchidos com pastas de hidróxido de cálcio / In vitro analysis of coronal bacterial leakage in teeth filled with calcium hydroxide pastes

Objetivo: Avaliar o efeito de barreira física de duas pastas de hidróxido de cálcio com diferentes veículos em canais radiculares expostos à saliva humana por um período de vinte dias. Método: Cinqüenta dentes humanos uniradiculares foram divididos em dois grupos experimentais com vinte dentes cada, um grupo controle positivo com 5 dentes e um grupo controle negativo com 5 dentes. O preparo químico-mecânico tipo coroa-ápice foi realizado sob irrigação com NaOCl a 1% e E.D.T.A. a 17%. Após esterilização dos dentes, foram aplicadas a pasta de hidróxido de cálcio em água destilada (Grupo I) e pasta de hidróxido de cálcio com paramonoclorofenol canforado (PMCC) em polietilenoglicol 400 (Grupo II). O comportamento do efeito de barreira física das pastas foi observado durante um período de 20 dias, através do uso de aparato nos quais foram inseridos meio de cultura Brain Heart Infusion (BHI), o dente com as referidas pastas e saliva humana em BHI, todos acomodados separadamente. Resultados: Após período analisado, ocorreu turvação em apenas 1 caso dos vinte espécimes (5%) do grupo com hidróxido de cálcio em água destilada (Grupo I). No grupo com hidróxido de cálcio e PMCC em polietilenoglicol 400 (Grupo II) ocorreu turvação em 5 meios de cultura (25%). Conclusão: Ambas as pastas de hidróxido de cálcio analisadas atuaram como barreira física à infiltração cervical de canais radiculares expostos ao meio contaminado, contudo observou-se que o grupo com hidróxido de cálcio em água destilada obteve menor número de espécimes infiltrados, com diferença estatística comprovada, em relação ao grupo com hidróxido de cálcio e PMCC em polietilenoglicol 400.

Objective: To evaluate the physical barrier effect of two calcium hydroxide pastes prepared with different vehicles in root canals exposed to human saliva for 20 days. Method: Fifty single-rooted human teeth were divided into two experimental groups with 20 teeth each, one positive control group with 5 teeth and one negative control group with 5 teeth. A crown-down chemomechanical preparation was performed under irrigation with 1% NaOCl and 17% EDTA. After sterilization of the teeth, the canals were filled with either a paste of calcium hydroxide and distilled water (Group I) or a paste of calcium hydroxide with camphorated paramonochlorophenol (PMCC) and polyethylene glycol 400 (Group II). The behavior of the physical barrier effect of the pastes was observed during 20 days, through the use of an apparatus in which were placed brain heart infusion (BHI) culture medium, the tooth filled with paste and human saliva in BHI, all of them accommodated separately. Results: After the established period, turbidity occurred in only 1 of the 20 specimens (5%) of the group filled with a paste of calcium hydroxide and distilled water (Group I). In the group filled with a paste of calcium hydroxide and PMCC in polyethylene glycol 400 (Group II) turbidity occurred in 5 specimens (25%). Conclusion: It may be concluded that both calcium hydroxide pastes analyzed in the study acted as a physical barrier to coronal leakage in root canals exposed to a contaminated environment; however, the group filled with calcium hydroxide and distilled water showed a smaller number of specimens with leakage, differing significantly from the group filled with calcium hydroxide with PMCC and polyethylene glycol 400.

Selamento imediato da dentina na otimização de coroas de cerâmicas puras / Immediate dentin sealing in pure ceramic crowns optimization

Na técnica convencional de cimentação em prótese fixa, o adesivo é aplicado e/ou fotopolimerizado somente na fase de cimentação da peça. Caso a dentina seja contaminada anteriormente, esta adesão é prejudicada. A dentina recém-preparada é considerada o substrato ideal para a adesão, pois não há risco de contaminação. Com base nessa ideia, tem sido sugerido que logo após o preparo e antes da moldagem, o mesmo seja selado com um adesivo dentinário. Esta técnica é denominada Selamento Imediato da Dentina (SID) e possui várias vantagens em relação à técnica convencional de cimentação. O objetivo deste trabalho é descrever e discutir esta técnica de aplicação clínica que contribui para o aumento da resistência e ajuda a evitar a sensibilidade dentária

In indirect restorations conventional luting, the adhesive is applied and/or light cured during the luting procedure, after provisional phase. If dentin is infected previously, this adhesion is impaired. The freshly cut dentin is considered the ideal substrate for dentin bonding, because there is no risk of contamination. Based on this idea, it has been suggested that after exposing dentin, it must be sealed with a dentin adhesive. This technique is called Immediate Dentin Sealing (IDS) and has several advantages over the conventional luting. The aim of this study is describe and discuss this clinical technique that contributes to increase dentin bond strength and prevents tooth sensitivity

Qualitative SEM/EDS analysis of microleakage and apical gap formation of adhesive root-filling materials

OBJECTIVE: The aim of this study was to compare the correspondence between gap formation and apical microleakage in root canals filled with epoxy resin-based (AH Plus) combined or not with resinous primer or with a dimethacrylate-based root canal sealer (Epiphany). MATERIAL AND METHODS: Thirty-nine lower single-rooted human premolars were filled by the lateral condensation technique (LC) and immersed in a 50-wt% aqueous silver nitrate solution at 37ºC (24 h). After longitudinal sectioning, epoxy resin replicas were made from the tooth specimens. Both the replicas and the specimens were prepared for scanning electron microscopy (SEM). The gaps were observed in the replicas. Apical microleakage was detected in the specimens by SEM/energy dispersive spectroscopy (SEM/EDS). The data were analyzed statistically using an Ordinal Logistic Regression model and Analysis of Correspondence (α=0.05). RESULTS: Epiphany presented more regions containing gaps between dentin and sealer (p<0.05). There was correspondence between the presence of gaps and microleakage (p<0.05). Microleakage was similar among the root-filling materials (p>0.05). CONCLUSIONS: The resinous primer did not improve the sealing ability of AH Plus sealer and the presence of gaps had an effect on apical microleakage for all materials.

Influence of marginal fit and cement types on microleakage of all-ceramic crown systems

The purpose of this study was to evaluate the effects of both marginal fit and cementing with different luting agents on the microleakage of all-ceramic crown systems. Thirty-six extracted upper central incisors were prepared for full-coverage crowns and were divided into three groups. Group 1: CAD/CAM-fabricated ZrO2, Group 2: Heat-pressed lithium-disilicate, and Group 3: Cast Cr-Co copings as the control group. Copings were made following standard techniques, and groups were assigned cementation with either self-adhesive resin cement (A) or glass-ionomer luting cement (B). The specimens were subjected to thermocycling, immersed in basic fuchsin solution, sectioned mesiodistally and buccolingually. The surface of each section was digitally photographed under a stereomicroscope. Microleakage was scored using a five-point scale, and the marginal gap was measured using image analysis software. Data were statistically analyzed using 2-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests (α: 0.05). The marginal discrepancy of each group was 82.7 ± 7 µm, 92.6 ± 4 µm and 96.5 ± 7 µm respectively. Group 1 showed significantly smaller gaps than Group 3 (P = 0.042). Self-adhesive resin cement (A) showed a lower level of microleakage than glass-ionomer luting cement (B) in all groups (P = 0.029). Microleakage scores of '0' were 83 percent for 1A, 50 percent for 1B, 50 percent for 2A, 16 percent for 2B, 33 percent for 3A and none for 3B. Marginal discrepancy and cement type both had significant effects on microleakage. Lower levels of microleakage were recorded with self-adhesive resin cement, while CAD/CAM-fabricated ZrO2 copings showed smaller marginal discrepancy and less microleakage in comparison to cast Cr-Co.

Metodologias aplicadas para análise da capacidade de selamento dos materiais retrobturadores: revisão da literatura / Methodologies for analysis for the sealing ability of the root-end filling materials: literature review

O objetivo deste estudo consistiu em comparar, por meio de revisão da literatura, as diversas metodologias utilizadas para análise da capacidade de selamento dos materiais retrobturadores. Assim como, verificar quais destes materiais retrobturadores são capazes de promover melhor selamento apical, prevenindo a percolação e o consequente insucesso da terapia endodôntica. Com base nos resultados demonstrados pela literatura, pode-se chegar às seguintes considerações: a infiltração por glicose e a infiltração bacteriana foram as metodologias que melhor avaliaram a capacidade de selamento apical. Entretanto, serão necessários diversos estudos para a total comprovação da infiltração por glicose. O MTA foi o material retrobturador com melhor capacidade de selamento apical, nas diversas metodologias aplicadas.

The objective of this study was to compare, by reviewing the literature, the various methodologies used to analyze the sealing ability of the root-end fillings materials. As well as, to verify which of these root-end fillings materials are able to promote better apical sealing, preventing percolation and the consequent failure of endodontic therapy. Based on the results demonstrated by the literature, one can come to these following considerations: glucose leakage and bacterial leakage were the methodologies that best evaluated the apical sealing ability. However, various studies will be needed for total attesting the infiltration by glucose. MTA as a root-end filling material provided better apical sealing ability, in the various methodologies.

Evaluation of the apical infiltration after root canal disruption and obturation

The aim of this study was to evaluate two root canal filling techniques used in teeth that had their apical foramen disrupted and compare the apical infiltration with an ideal clinical situation. Twenty-seven freshly extracted single-rooted teeth were selected and radiographed to confirm the existence of a single and straight root canal. The crowns were removed at a mean distance of 11 mm from the apex. The teeth had the root canals instrumented and were randomly assigned to 3 groups (n=9): ND group - root canals were filled using the lateral compaction technique and no disruption was performed; DRF group - the apical constriction was disrupted by advancing a #40 K-file 1 mm beyond the original working length, the canals were reinstrumented to create an apical ledge at 1 mm from the apical foramen and were obturated with a master gutta-percha cone with same size as the last file used for reinstrumentation; DF group - the teeth had the apical constriction disrupted and the canals were obturated with a master gutta-percha cone that fit at 1 mm from the apex. The teeth were submitted to dye leakage test with Rhodamine B for 7 days, using vaccum on the initial 5 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. There was no statistically significant difference (p>0.05) between the groups that had the apical foramen disrupted (DF, DRF), but significant difference was found between the disrupted groups and the non-disrupted one (p<0.01). In conclusion, none of the evaluated techniques was able to prevent apical infiltration, so working length so the working length determination has to be established and maintained carefully.

Evaluation of the apical seal after intraradicular retainer removal with ultrasound or carbide bur

There are situations in which intraradicular retainers have to be removed and replaced. The objective of this research was to evaluate the apical seal after the removal of a custom cast post and core with a carbide bur or with an ultrasound apparatus. Twenty five roots of extracted human incisors were used. They were endodontically treated and prepared to receive the posts. The posts and cores were cast with 2 types of dental alloys, CuAlZn and PdAg, and were cemented with zinc phosphate cement. After 24 hours, they were removed using the two above mentioned techniques. Then, the roots had their external surface made impermeable by two layers of cyanoacrylate adhesive, leaving only the cervical area for dye penetration. The teeth were immersed in rhodamine for 24 hours. They were then cut and observed under an optical microscope and analyzed with appropriate software (Imagelab). The results were submitted to ANOVA, and they evidenced that, regarding the alloy factor, PdAg posts presented a larger mean infiltration value (2.23 ± 0.48 mm) as compared to the posts made of CuAlZn (1.39 ± 0.48 mm) (p = 0.025). Regarding the technique factor, there was no significant difference (p = 0.9) between the removal of the intraradicular retainer using ultrasound (1.99 ± 0.62 mm) or using a rotating cutting instrument (1.62 ± 0.62 mm). Under these experimental conditions, it was possible to conclude that the degree of apical leakage was directly related to the alloy type, and it was present in both techniques used.

Há situações que exigem a remoção ou substituição de retentores intra-radiculares. O objetivo deste trabalho foi avaliar o selamento apical do material obturador após a remoção de pino intra-radicular metálico fundido com instrumento cortante rotatório ou com aparelho de ultra-som. Utilizaram-se 25 raízes de incisivos humanos extraídos, que foram endodonticamente tratadas e preparadas para receberem os pinos. Os retentores intra-radiculares foram fundidos com 2 tipos de ligas odontológicas, CuAlZn e PdAg, e foram cimentados com cimento de fosfato de zinco. Após 24 horas, foram removidos com as 2 técnicas citadas. Em seguida, os dentes foram impermeabilizados com cianoacrilato de etila, permitindo a entrada do corante apenas por via cervical. Os dentes foram imersos em rodamina por 24 horas, depois foram clivados e observados em microscópio óptico de luz e analisados em "software" próprio (Imagelab). Os resultados foram submetidos à análise de variância e mostraram que, para o fator liga, os pinos de PdAg geraram uma média de infiltração maior (2,23 ± 0,48 mm) do que os pinos de CuAlZn (1,39 ± 0,48 mm), com p = 0,025; para o fator técnica, não houve diferença significante, com p = 0,9, entre a remoção com ultra-som (1,99 ± 0,62 mm) e a remoção com instrumento cortante rotatório (1,62 ± 0,62 mm). Nestas condições experimentais, foi possível concluir que o grau de infiltração apical está relacionado com o tipo de liga, e a infiltração esteve presente em ambas as técnicas utilizadas.

In vitro evaluation of marginal leakage in bonded restorations, with mechanical or chemical-mechanical (Carisolv) removal of carious tissue

This study carried out an in vitro evaluation and comparison of the occurrence of marginal leakage in bonded restorations using mechanical or chemical-mechanical (Carisolv) removal of carious tissue. For that purpose, 40 extracted decayed human molars were divided into 4 groups: GI (burs + Prime & Bond NT + TPH), GII (Carisolv + Prime & Bond NT + TPH), GIII (burs + SBMP + Z100) and GIV (Carisolv + SBMP + Z100). After accomplishment of the restorations and thermal cycling, the teeth were exposed to dye, sectioned and qualitatively evaluated. The results demonstrated that the system of removal of carious tissue did not influence the results of microleakage at any of the cavity margins. At dentinal margins, use of the Prime & Bond NT + TPH restorative system allowed the occurrence of less microleakage than the SBMP + Z100 system.

Este estudo avaliou e comparou in vitro a ocorrência da infiltração marginal em restaurações adesivas, com a utilização de remoção mecânica e químico-mecânica do tecido cariado. Para a proposição, 40 dentes molares humanos extraídos cariados foram divididos em quatro grupos: GI (brocas + Prime & Bond NT + TPH), GII (Carisolv + Prime & Bond NT + TPH), GIII (brocas + SBMP + Z100) e GIV (Carisolv + SBMP + Z100). Após a execução das restaurações e termociclagem, os dentes foram expostos a corante, seccionados e avaliados qualitativamente. Os resultados demonstraram que o sistema de remoção de tecido cariado não influenciou a ocorrência de microinfiltração em quaisquer margens cavitárias. Nas margens dentinárias, a utilização do sistema restaurador Prime & Bond NT + TPH demonstrou menor ocorrência de microinfiltração do que o sistema SBMP + Z100.

Estudo in vitro da microinfiltração em fóssulas e fissura seladas com selante resinoso e compômero / Study in vitro of the microleakage in the pits and fissurs sealed with resin sealant and compomer

Objetivo: O propósito deste trabalho foi comparar, in vitro, amicroinfiltração em fossas e fissuras de uma resina composta® modificada por poliácido (Dyract ) que foi utilizada como® selante e um selante resinoso (Fluoroshield ). Método:Utilizou-se 36 pré-molares íntegros, divididos em três grupos:GI (Flu.), GII (Dyr.) e GC (Controle - sem selante). Apósselamento, os dentes foram submetidos a ciclos de DES-RE, eem seguida simulando alto desafio cariogênico. Os dentesforam submersos em solução de Nitrato de Prata a 50 por cento paraanálise da microinfiltração. Em seguida, foram incluídos emresina epóxica. As coroas foram cortadas no sentido vestibulolingualpara avaliação do grau de microinfiltração na interfaceesmalte/selante. Para a classificação da microinfiltração,avaliada por três examinadores, foram utilizados escores 0-ausência de corante, 1-metade do sulco e 2-todo sulco.Resultados: Os resultados foram tratados estatisticamente porANOVA, Kruskal-Wallis e Mann-Whitney (p<0,05), sendo osPostos Médios: GI (35,97), GII (37,53), GC (90,00). Não houvediferença estatisticamente significante entre os materiais.® Conclusão: O Dyract não apresenta, in vitro, evidências demicroinfiltração. Porém, não deve-se descartar a necessidadede estudos clínicos longitudinais que comprovem suaresistência e retentividade como a resina composta e suaspropriedades anticariogênicas como o ionômero de vidro.

Postes radiculares y sellado endodóntico / Radicular posts and endodontic sealing

Todos los dientes tratados endodónticamente necesitan ser restaurados; en muchos de los casos estará indicada la colocación de un poste, ya sea prefabricado o colado. Crear el espacio para poste requiere eliminar parte de la gutapercha y del cemento sellador, así como manipular el conducto radicular, con lo que se incrementa el riesgo de debilitar o perforar la raíz. El objetivo de la presente revisión es ofrecer un punto de vista de la forma en que la preparación del espacio para un poste intrarradicular puede provocar la filtración coronal de bacterias que conllevarían al fracaso del tratamiento endodóntico realizado

Avaliação da microinfiltração marginal em restaurações de resina composta: efeito de adesivos dentinários / Evaluation of marginal microleakage in composite resin restoration: efeito de adesivos dentinários

Este estudo teve como objetivo avaliar o grau de microinfiltração marginal de restaurações de resina composta. Os materiais utilizados foram resina composta Charisma e os adesivos dentinários, Scothbond Multiuso Plus, Single Bond e Prompt L-Pop. Vinte e um dentes pré-molares humanos, recém extraídos foram selecionados e divididos em três grupos, nestes foram preparadas na face vestibular e lingual cavidades padronizadas classe V, tendo a margem gengival localização em dentina e envolvidos. Os dentes restaurados foram isolados com resina epóxica (araldite/Ciba), preservando as restaurações e 2,0mm ao seu redor. Em seguida foram submetidos à ciclagem térmica e imersos em Rodamina B a 0,2%. A extensão da penetração por método não paramétrico (teste de significância para igualdade de duas proporções), com p<0,05. Os resultados de microinfiltração marginal encontrados, para cada um dos três sistemas adesivos utilizados, não mostarram diferença estatisticamente significante

Microleakage on class V glass ionomer restorations after cavity preparation with aluminum oxide air abrasion

Este estudo in vitro avaliou a microinfiltração marginal em cavidades classe V preparadas com jato de óxido de alumínio e restauradas com diferentes sistemas ionôméricos. As cavidades foram preparadas nas superfícies vestibular e lingual de 15 terceiros molares hígidos e foram divididas em três grupos com 10 cavidades cada um. Os seguintes materiais foram utilizados: no grupo I, cimento de ionômero de vidro convencional (Ketac Fil) e nos grupo II e III, cimentos de ionômero de vidro modificado por monômeros resinosos (Vitremer e Fuji II LC, respectivamente). O preparo cavitário foi realizado por meio da aplicação do jato de óxido de alumínio (Kreativ Mach 4.1; New Image), com partículas de 27,5 µm. Após a restauração das cavidades, os dentes foram armazenados durante 24 h em água destilada a 37ºC, polidos e então submetido a termociclagem (500 ciclos), imersos em Rodamina B a 0,2% por 24 h, incluídos e seccionados. A análise da microinfiltração marginal foi realizada por meio de um microscópio óptico acoplado a uma câmera e a um computador. As imagens obtidas foram digitalizadas e analisadas utilizando um software que permite uma análise quantitativa padronizada da microinfiltração, em milímetros. As médias (%) obtidas foram: oclusal - I: 25,76 mais ou menos 34,35; II: 20,00 mais ou menos 42,16; III: 28,25 mais ou menos 41,67; cervical I: 23,72 mais ou menos 41,84; II: 44,22 mais ou menos 49,69; III: 39,27 mais ou menos 50,74. Os dados foram submetidos à análise estatística, utilizando os testes de Kruskall-Wallis e Wilcoxon. Não houve diferença estatisticamente significante (p>0.05) entre os materiais testados nem entre as margens oclusal e cervical. Conclui-se que em cavidades classe V preparadas com ar abrasão e restauradas com cimentos de ionômero de vidro convencional e modificados por monômeros resinosos não houve completo vedamento marginal.