Qualitative analysis of files of four different rotary systems, before and after being used for the twelfth time.

The aim of this study was to make a comparative evaluation of the surface topography of the cervical third and tip of four different rotary systems, before and after being used 12 times, in resin blocks with simulated root canals with standardized 45° curvatures, and analyzed by scanning electronic microscopy (SEM). A total of 1,440 resin blocks with simulated root canals and standardized curvatures were used. The blocks were divided into four groups and prepared by the crown down technique according to the manufacturers' recommendations: Group 1 (G1)--K3®, Group 2 (G2)--Protaper Universal®, Group 3 (G3)--Twisted Files®, and Group 4 (G4)--Biorace®. After each preparation, the instruments were washed and autoclaved. A total of 24 instruments were selected, being three new instruments and three after having been used for the 12th time, from each group. These instruments were analyzed by SEM. To perform the evaluation, 24 micrographs were observed by 12 evaluators who attributed a score to the images according to a template. In the qualitative analysis of the cervical region and tip of new instruments, it was observe that the files of Groups G4 and G2 were the least rough and those of G1, the roughest. In the same manner, the cervical region of the instruments was qualitatively analyzed after the 12th time of using them, and there was no statistically significant difference at a level of 1% (ANOVA P < 0.01) between G2 and G4 as well as between G1 and G3. As regards the tip, it was observed that there was no statistically significant difference, at a level of 1%, between the groups: G1 and G3, G1 and G4, and between G3 and G4, and there was statistically significant difference at a level of 1%, between group G2 and the other groups, with G3 having the greatest roughness (ANOVA P < 0.01).

Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy.

Low-level laser therapy is a tool employed in the management of post-operative inflammation process and in the enhancement of reparative process. The aim of the study was to perform histological evaluation of dental and periodontal ligament of rats central upper-left incisor teeth re-implanted and irradiated with low-level laser (InGaAl, 685 nm, 50 J/cm(2)) 15, 30, and 60 days after re-implantation. Seventy-two male rats had the central upper left incisor removed and kept for 15 min on dry gauze before replantation. Laser was irradiated over the root surface and empty alveolus prior replantation and over surrounding mucosa after the re-implantation. After histological procedures, all slices were analyzed regarding external resorption area and histological aspects. We observed an increase of root resorption (p < 0.05) in the control group compared to the laser group at 15, 30, and 60 days. These results showed that the laser groups developed less root resorption areas than the control group in all experimental periods. Additionally, histological analysis revealed less inflammatory cells and necrotic areas in laser groups.

Radiopacidade de 4 cimentos obturadores através da análise tomográfica / Radiopacity of 4 cements obturators through the tomographic analysis

Este trabalho visou analisar a radiopacidade dos seguintes cimentos obturadores: AH Plus,Sealer 26, MTA Filappex e N- Rickert, visto que, é uma propriedade desejada nos cimentos endodônticos,pois é através dela que visualizamos o preenchimento correto do canal radicular. Paraesta análise, foram feitas amostras de cada cimento segundo as especificaçôes da ANSI/ADA eutilizada de maneira inovadora tomografia computadorizada, comparando-as com o chumboatravés da escala de Hounsfield. Os cimentos AH PLus e MTA Filappex são mais radiopacos doque o N-Rickert e o Sealer 26, portanto, de melhor visualização da obturação do canal.

This work aims to analyze the radiopacity of the following sealers: AH Plus, Sealer 26, MTAFilappex and N-Rickert, since it is adesired property in endodontic sealers, because throughit we look to the correct completion of the root canal. For this analysis, we made samples 01each sealer according to the specifications of ANSI/ADA and use of computed tomography ininnovative ways, comparing with the lead through the Hounsfield scale. The MTA and AH Plussealer Filappex are more radiopacity than N-Rickert and Sealer 26, therefore, better visualizationof the root canal filling.

Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions.

The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5% and 1% sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5% NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1% sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5 percent and 1 percent sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5 percent NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1 percent sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

Avaliação da permeabilidade radicular em dentes com rizogênese incompleta após aplicação de hidróxido de cálcio como medicação intracanal / Root permeability evaluation in immature permanent teeth after calcium hydroxyde application as intra root medication

Introdução - Foi avaliada a possível variação da permeabilidade dentinária radicular, em dentes com rizogênese incompleta, após medicação com hidróxido de cálcio veiculado em solução anestésica. Material e Métodos - Decorrido o prazo experimental, os dentes foram re-preparados com quatro diferentes técnicas de remoção da medicação, avaliando-se quantitativamente o índice de permeabilidade dentinária radicular, através da penetração do corante azul de metileno. Observou-se existir diferença estatisticamente significante quanto à porcentagem de penetração de corante em função do tipo de técnica usada na remoção da medicação. Resultados - O uso do EDTA-T seguido ao seu final pelo creme de Endo-PTC neutralizado pelo hipoclorito de sódio a 1%, foi o que melhor proporcionou um aumento no índice de permeabilidade pós-medicação, devolvendo ao dente a condição prévia de permeabilidade conseguida após o preparo químico-cirúrgico, não havendo diferença estatisticamente significante ao nível de 5% entre o Grupo 2 e 6, nos diferentes terços radiculares. Conclusões - A medicação com hidróxido de cálcio interferiu, de forma decisiva, no índice de permeabilidade dentinária radicular, independente do terço radicular analisado

Análise comparativa entre dois métodos para determinação do grau de curvatura de canais radiculares / Comparative analysis between two methods for root canals curvature degree determination

O objetivo deste estudo foi comparar dois métodos para determinação do grau de curvatura de canais radiculares (ângulo de Schneider e método FKG). Métodos - Foram selecionadas 23 radiografias, realizadas pela técnica do paralelismo, de primeiros molares inferiores humanos com ápice completo e sem tratamento endodôntico, do Curso de Especialização em Endodontia da APCD - Regional São Caetno do Sul. Para a determinação do ângulo de Scheneider, as radiografias foram postas sobre um negatoscópio e nelas foram localizados três pontos sobre a raiz mesial: ponto A - orifício da entrada dos canais radiculares; ponto B - início da curvatura do canal radicular e ponto C - vértice radiográfico. O ponto A foi unido ao B por uma reta e este ao C por outra reta. Estas retas foram transferidas para uma folha, onde com o auxílio de um transferidor, determinou-se o ângulo de curvatura, classificando-o de acordo com a sua severidade em suave, moderada ou severa. Para determinar o grau de curvatura pelo método da FKG, procedeu-se sobrepondo a radiografia sobre a tabela com a da radiografia. As angulações da FKG foram mensuradas de acordo com o método de Schneider para transformar suas medidas em graus, permitindo uma análise comparativa entre os dois métodos. Resultados - A análise estatística dos resultados mostrou existir uma diferença estatisticamente significante ao nível de 1% (teste de Wilcoxon). Conclusões - Não há uma padronização entre os métodos comparados. Todas as angulações classificadas como moderadas pelo método de Scheneider foram consideradas suaves pela tabela da FKG e as angulações suaves e moderadas para a tabela da FKG foram consideradas severas pelo método de Scheneider. A classificação segundo a metodologia de Scheneider se mostra mais confiável em comparação à técnica com o uso da tabela da FKG