RESUMO
The aim of this study was to evaluate the capacity of conventional irrigation, passive ultrasonic irrigation (PUI), and Easy Clean for removing calcium hydroxide-based root canal dressing from oval root canals. Thirty mandibular uniradicular incisors with oval canals were used, and subjected to chemical-mechanical preparation with Reciproc R40 instruments. The main canal was filled with a paste based on Ca(OH)2 P.A., iodoform and propylene glycol in the ratio of 3:1:1. The teeth were stored in 100% humidity at a temperature of 37°C for 14 days. Afterwards, the teeth were divided into three groups (n = 10) according to the method of irrigation used (conventional irrigation, PUI, and Easy Clean). The specimens were analyzed by computed microtomography at three time intervals: before placing the root canal dressing, with the root canal dressing in place, and after application of the irrigation methods for removing it. The data were submitted to Kruskal-Wallis and Dunn tests for analyzing the canal as a whole, and Friedman and Dunn for analyzing the root thirds. The results showed that conventional irrigation was less efficient for removing the root canal dressing in comparison with the methods that agitated the irrigant solution (p < .05). When the root canal was analyzed as a whole, Easy Clean, and PUI were similar (p > .05). In analysis of the thirds, Easy Clean was more efficient than conventional irrigation in all the thirds, while PUI showed this behavior only in the cervical third (p < .05). The authors concluded that in oval canals, none of the irrigation methods were capable of removing all the root canal dressing, however, the methods that agitated the irrigant solution were more efficient than conventional irrigation.
RESUMO
Objetivo: avaliar a influência que as principais soluções irrigadoras endodônticas exercem na resistência adesiva à tração de restaurações adesivas realizadas na dentina superficial coronária de dentes bovinos, e depois de realizados os testes analisar as superfícies dentinárias em MEV. Material e Método: Foram selecionados 48 dentes incisivos bovinos, que tiveram as coroas seccionadas na porção cervical a 2mm da junção amelocementária, e inclusas em resina epóxi. O esmalte da face vestibular dos dentes foi desgastado com lixas dágua acopladas à máquina politriz para exposição da área de dentina a ser avaliada, e os grupos experimentais foram divididos em grupos, de acordo com substâncias irrigadoras utilizadas no tratamento dos espécimes: G1 Soro fisiológico 0,9% NaCl (controle), G2 Clorexidina líquida a 2%, G3 Hipoclorito de sódio a 2,5%, G4 Hipoclorito de sódio a 1%. Após o tratamento dos espécimes com as soluções irrigadoras e aplicação do material restaurador, foram realizados os testes de tração na máquina de ensaio universal EMIC®, e após o teste foi selecionado um corpo de prova de cada grupo para análise em MEV para avaliação do tipo de fratura ocorrida. Resultados: os resultados médios e desvio padrão obtidos foram: G1=14,52 MPa (11,02); G2=17,96 MPa (7,64); G3=15,61 MPa (9,30); G4=19,24 MPa (5,92). Conclusões: com base na metodologia empregada podemos concluir que não houve diferença estatística entre os valores de força de adesão obtidos após o tratamento das superfícies dentinárias. A análise em MEV demonstrou fraturas mistas, onde há o envolvimento da interface (camada híbrida) ou mais de um substrato (fratura coesiva em resina, fratura coesiva em dentina).
Aim: The aim of this study was to evaluate the influence of endodontic irrigants on tensile bond strength of adhesive restorations made on coronal surfaces of bovine teeth and after tests to analyze the dentin surfaces by SEM. Methodology: Forty eight bovine incisors teeth were selected. The teeth have crowns split in the cervical portion to 2mm from the junction amelo-cementum, and were included in epoxi resin. The enamel vestibular faces of the teeth were worn for exposure the area of dentin to be evaluated. The experimental groups were divided according to the solution used: G1- 0,9% NaCl, G2- 2% chlorhexidine solution; G3- 2,5% NaOCl; G4- 1% NaOCl.. Results: the results and the standard deviation were: G1=14,52 MPa (11,02); G2=17,96 (7,64); G3=15,61 (9,30); G4=19,24 (5,92). Conclusions: Under the conditions of this study it can be concluded that there were no statistically significant differences among the groups. SEM analysis showed mixed fractures, where there is involvement of the interface (hybrid layer) or over a substrate (cohesive failure in resin, cohesive failure in dentin).
RESUMO
OBJECTIVE: The aim of this study was to evaluate the biocompatibility of Portland cement with the addition of iodoform, compared to MTA (ProRoot). STUDY DESIGN: Eighteen Wistar albino rats were divided into 3 groups of 6 animals each. Polyethylene tubes were filled either with freshly mixed MTA or Portland cement mixed with iodoform (20% wt/wt) and implanted subcutaneously. An empty tube served as control. After 7, 30, or 60 days, the implants together with the surrounding tissues were removed in blocks. Sections were evaluated for the presence and thickness of a fibrous capsule, presence of granulation tissue, and the severity of inflammatory response. Data were submitted to nonparametric statistical analysis with individual comparisons between groups at a significance level of P < 0.05. RESULTS: There were no differences between inflammatory responses at 7 and 30 days. After 60 days from surgical removal, there was significantly more tissue reaction to the MTA and Portland cement compared to the control group. CONCLUSION: There were no significant differences regarding inflammatory responses between MTA and Portland cement with iodoform after 7, 30, or 60 days. After 60 days, the fibrous capsule around the Portland cement appeared more organized than tissue surrounding MTA implants. After 60 days, there was still a significantly increased tissue reaction to the 2 cements compared to the empty polyethylene tubes.