Canal Transportation, Centering Ability, and Dentin Removal after Instrumentation: A Micro-CT Evaluation.

AIM: The aim of this study is to evaluate and compare root canal transportation, centering ability, and amount of dentin removed after root instrumentation with different rotary and reciprocating systems, using micro-computed tomography (micro-CT). MATERIALS AND METHODS: Forty curved mesial canals of lower molars were selected and divided into four experimental groups (n = 10) according to the system used: protaper next (PTN), wave one gold (WOG), prodesign logic (LOG), and vortex blue (VTX). The roots were scanned before and after instrumentation using micro-CT, with a 16 µm isotropic resolution. RESULTS: Data were statistically analyzed using the Bioestat and the significance level was set at 0.05. For canal transportation, no significant differences were verified between the groups at 6 mm or 9 mm from the apex. At the apical third, LOG had a smaller mesial deviation when compared with PTN. A significant difference was found at the apical and coronal thirds, though with LOG having the best centering ability at the apical third and the worst one at the coronal third. All systems caused a greater wear at the coronal third (9 mm), decreasing at the apical one (3 mm), with statistically significant differences. LOG removed less dentin from the apical third (3 mm) than did the other instruments. CONCLUSION: The systems evaluated presented different results for canal transportation, centering ability, and dentin removal at each third. CLINICAL SIGNIFICANCE: The systems were evaluated together to evaluate neither the marked dental deviations nor the long-term signifiers of the databases and they were evaluated within the limits of normality. Therefore, they can be used without risks of embrittlement of the dental roots.

Cytotoxicity assessment of 1% peracetic acid, 2.5% sodium hypochlorite and 17% EDTA on FG11 and FG15 human fibroblasts.

The aim of this study was to evaluate the cytotoxic effects of 2. 5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 1% peracetic acid (PAA) on human fibroblasts. FG11 and FG15 cell lines were cultured in 24-well cell culture plates for cell proliferation assessment and 96-well cell culture plates for the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay; Dulbecco's modified Eagle's medium (DMEM) was used as control data. The experimental solutions were used at 0. 01%, 0. 05%, and 0. 1% dilutions and assessed at 1-, 2-, and 4-hour intervals. Data were subjected to statistical analysis by two-way analysis of variance (ANOVA), followed by the Bonferroni test at a significance level of p <0. 05. The assessment of cell proliferation in this study showed cytotoxicity to the fibroblasts with 2. 5% NaOCl for all three dilutions at all time intervals, 17% EDTA for the 0. 05% and 0. 1% dilutions at the 2- and 4-hour intervals, and 1% PAA for all three dilutions at the 4-hour interval. The cell viability assay (MTT assay) for fibroblasts showed 2. 5% NaOCl to be cytotoxic at the 0. 05% and 0. 1% dilutions at all time intervals, 17% EDTA to be cytotoxic at the 0. 1% dilution at the 2- and 4-hour intervals, and 1% PAA to be cytotoxic at the 0. 1% dilution at the 2- and 4-hour intervals. In conclusion, 1% PAA was less cytotoxic than 2. 5% NaOCl and 17% EDTA.

O objetivo do presente estudo foi o de avaliar os efeitos citotóxicos de hipoclorito de sódio (NaOCl) a 2,5%, ácido etilenodiaminotetracético (EDTA) a 17% e ácido peracético (PAA) a 1% em fibroblastos humanos. As linhagens celulares FG11 e FG15 foram colonizadas em 24-well cell plates para avaliaçâo da proliferaçâo celularr e em 96-well cell plates para o ensaio de MTT; O médio modificado Dulbecco's Eagle's (DMEM) foi usado como controle. As soluções experimentais foram usadas com diluições de 0,01%, 0. 05%, e 0,1% e avaliadas com 1, 2 e 4 horas de intervalo. Os dados foram submetidos à análise estatística pelo two-way ANOVA, seguido do teste de Bonferroni com nivel de significância dep <0. 05. A avaliaçâo da proliferação celular neste estudo mostrou o NaOCL a 2,5% como citotóxico nas 3 diluições e 3 intervalos de tempo, o EDTA a 17% nas diluições de 0,05% e 0,1% nos intervalos de 2 e 4 horas, e o PAA a 1% em todas as diluições no intervalo de 4 horas. O teste de viabilidade cellular (MTT) mostrou o NaOCl a 2,5% citotóxico a 0,05% e 0,1% em todos os intervalos, o EDTA a 17% citotóxico nas diluições de 0,1% nos intervalos de 2 e 4 horas e o PAA a 1% citotóxico na diluição de 0,1% nos intervalos de 2 e 4 horas. Como conclusão o PAA a 1% mostrou-se menos citotóxico que o NaOCl a 2,5%> e o EDTA a 17%>.

Cytotoxicity assessment of 1% peracetic acid, 2,5% sodium hypochlorite and 17% EDTA on FG11 and FG15 human fibroblasts / Avaliação da citotoxicidade de ácido peracético a 1%, hipoclorito de sòdio a 2,5% e EDTA a 17% em fibroblastos humanos FG11 e FG15

The aim of this study was to evaluate the cytotoxic effects of 2.5% sodium hypochlorite (NaOCl), 17% ethylenediamine tetraacetic acid (EDTA), and 1% peracetic acid (PAA) on human fibroblasts. FG11 and FG15 cell lines were cultured in 24well cell culture plates for cell proliferation assessment and 96well cell culture plates for the methylthiazolyldiphenyltetrazolium bromide (MTT) assay; Dulbecco's modified Eagle's medium (DMEM) was used as control data. The experimental solutions were used at 0.01%, 0.05%, and 0.1% dilutions and assessed at 1, 2, and 4hour intervals. Data were subjected to statistical analysis by twoway analysis of variance (ANOVA), followed by the Bonferroni test at a significance level of p <0.05. The assessment of cell proliferation in this study showed cytotoxicity to the fibroblasts with 2.5% NaOCl for all three dilutions at all time intervals, 17% EDTA for the 0.05% and 0.1% dilutions at the 2and 4hour intervals, and 1% PAA for all three dilutions at the 4hour interval. The cell viability assay (MTT assay) for fibroblasts showed 2.5% NaOCl to be cytotoxic at the 0.05% and 0.1% dilutions at all time intervals, 17% EDTA to be cytotoxic at the 0.1% dilution at the 2and 4hour intervals, and 1% PAA to be cytotoxic at the 0.1% dilution at the 2and 4hour intervals. In conclusion, 1% PAA was less cytotoxic than 2.5% NaOCl and 17% EDTA (AU)

O objetivo do presente estudo foi o de avaliar os efeitos citotóxicos de hipoclorito de sódio (NaOCl) a 2,5%, ácido etilenodiaminotetracético (EDTA) a 17% e ácido peracético (PAA) a 1% em fibroblastos humanos. As linhagens celulares FG11 e FG15 foram colonizadas em 24well cell plates para avaliação da proliferação celularr e em 96well cell plates para o ensaio de MTT; O médio modificado Dulbecco's Eagle's (DMEM) foi usado como controle. As soluções experimentais foram usadas com diluições de 0,01%, 0.05%, e 0,1% e avaliadas com 1, 2 e 4 horas de intervalo. Os dados foram submetidos à análise estatística pelo twoway ANOVA, seguido do teste de Bonferroni com nível de significância de p <0.05. A avaliação da proliferação celular neste estudo mostrou o NaOCL a 2,5% como citotóxico nas 3 diluições e 3 intervalos de tempo, o EDTA a 17% nas diluições de 0,05% e 0,1% nos intervalos de 2 e 4 horas, e o PAA a 1% em todas as diluições no intervalo de 4 horas. O teste de viabilidade cellular (MTT) mostrou o NaOCl a 2,5% citotóxico a 0,05% e 0,1% em todos os intervalos, o EDTA a 17% citotóxico nas diluições de 0,1% nos intervalos de 2 e 4 horas e o PAA a 1% citotóxico na diluição de 0,1% nos intervalos de 2 e 4 horas. Como conclusão o PAA a 1% mostrouse menos citotóxico que o NaOCl a 2,5% e o EDTA a 17% (AU)

Efectiveness of the waveone and ProTaper D systems for removing gutta-percha with or without a solvent.

Endodontic retreatment requires complete removal of the filling material and access to the apical foramen. The purpose of this study was to evaluate the effectiveness of the Wave One reciprocating system and compare it to the ProTaper D rotarysystem, with or without the use of a solvent, in removing filling material from root canals. The time required for each filling removal technique employed was also determined and compared. Forty extracted human mandibular premolars with a single, straight, flattened canal were prepared and filled. They were divided into four groups (n = 10): Group 1: ProTaper D Ni Ti rotary instruments; Group 2: ProTaper D Ni Tirotary instruments, with a solvent; Group 3: Wave One primary instrument; and Group 4: Wave One primary instrument, with a solvent. The teeth were then split along their long axis and photographed using an operating microscope with 5Xmagnification. The amount of remaining filling material was assessed with Image Tool software. The results were compared using the Kruskal Wallis test (p <0.05). There was no significant difference between groups regarding the amount of residual filling material (p > 0.05). Operative time was significantly longer in Group 3 than in groups 1, 2 and 4 (p <0.05). The Wave One system and the ProTaper D system were equally effective, with or without a solvent. The time required to remove the filling material from the canals was significantly longer in Group 3 than in the other groups.

No retratamento endodôntico, a completa remoção do material obturador e o acesso ao forame apical são necessários para permitir a limpeza do sistema de canais. O propósito deste estudo foi avaliar a eficácia do sistema reciprocante WaveOne ecomparálaao sistema rotatório ProTaper Universal, com ousem o uso de solvente, na remoção do material obturador. O tempo necessário a cada técnica empregada foi determinado e comparado. Quarenta pré-molares inferiores humanos extraídoscom canal único, reto e achatado foram preparados e obturados. Foram então divididos em quatro grupos (n = 10) de acordo como sistema utilizado, como segue. Grupo 1: ProTaper D Niti; Grupo 2: Sistema ProTaper D com solvente; Grupo 3: Sistema WaveOne instrumento Primary; e Grupo 4: Sistema WaveOne instrumento Primary com solvente, sendo o tempo registrado. Os dentes foram clivados longitudinalmente e fotografados utilizando microscópio operatório com aumento de 5 vezes. A quantidade de material remanescente foi avaliada com o uso do software Image Tool 3.0. Os resultados foram comparados utilizando o teste de Kruskal Wallis(p < 0.05). Em relação aos resultados, não houve diferença significativa entre os gruposquanto à quantidade de material obturador residual (p > 0.05). O tempo operatório no Grupo 3 foi significativa mente maior do que nos grupos 1, 2 e 4 (p < 0.05). O sistema WaveOne foi tão efetivo quanto o ProTaper D, com ou sem solvente. tempo necessário à des obturação dos canais no Grupo 3 (WaveOne sem solvente) foi significativamente maior do que nos demais grupos.

Effectiveness of the waveone and protaper D systems for removing gutta-percha with or without a solvent / Eficiência dos sistemas waveone e protaper D na remoção de guta-percha com ou sem uso solvente

Endodontic retreatment requires complete removal of the filling material and access to the apical foramen. The purpose of this study was to evaluate the effectiveness of the WaveOne reciprocating system and compare it to the ProTaper D rotary system, with or without the use of a solvent, in removing filling material from root canals. The time required for each filling removal technique employed was also determined and compared. Forty extracted human mandibular premolars with a single, straight, flattened canal were prepared and filled. They were divided into four groups (n = 10): Group 1: ProTaper D NiTi rotary instruments; Group 2: ProTaper D NiTi rotary instruments, with a solvent; Group 3: WaveOne primary instrument; and Group 4: WaveOne primary instrument, with a solvent. The teeth were then split along their long axis and photographed using an operating microscope with 5X magnification. The amount of remaining filling material was assessed with Image Tool software. The results were compared using the KruskalWallis test (p <0.05). There was no significant difference between groups regarding the amount of residual filling material (p > 0.05). Operative time was significantly longer in Group 3 than in groups 1, 2 and 4 (p < 0.05). The WaveOne system and the ProTaper D system were equally effective, with or without a solvent. The time required to remove the filling material from the canals was significantly longer in Group 3 than in the other groups.

No retratamento endodôntico, a completa remoção do material obturador e o acesso ao forame apical são necessários para permitir a limpeza do sistema de canais. O propósito deste estudo foi avaliar a eficácia do sistema reciprocante WaveOne e comparála ao sistema rotatório ProTaper Universal, com ou sem o uso de solvente, na remoção do material obturador.O tempo necessário a cada técnica empregada foi determinado e comparado. Quarenta prémolares inferiores humanos extraídos com canal único, reto e achatado foram preparados e obturados. Foram então divididos em quatro grupos (n = 10) de acordo com o sistema utilizado, como segue. Grupo 1: ProTaper D Niti; Grupo 2: Sistema ProTaper D com solvente; Grupo 3: Sistema WaveOne instrumento Primary; e Grupo 4: Sistema WaveOne instrumento Primary com solvente, sendo o tempo registrado. Os dentes foram clivados longitudinalmente e fotografados utilizando microscópio operatório com aumento de 5 vezes.A quantidade de material remanescente foi avaliada com o uso do software Image Tool 3.0. Os resultados foram comparados utilizando o teste de KruskalWallis( p < 0.05). Em relação aos resultados, não houve diferença significativa entre os grupos quanto à quantidade de material obturador residual (p > 0.05). O tempo operatório no Grupo 3 foi significativa mente maior do que nos grupos 1, 2 e 4 (p < 0.05).O sistema WaveOne foi tão efetivo quanto o ProTaper D, com ou sem solvente.tempo necessário à desobturação dos canais no Grupo 3 (WaveOne sem solvente) foi significativamente maior do que nos demais grupos.

A comparison of shaping ability using ProFile, GT file, and Flex-R endodontic instruments in simulated canals.

A total of 160 resin-simulated canal blocks with 20-degree or 30-degree curvature were prepared by ProFile rotary instruments, GT rotary files, and the balanced force technique with Flex-R files. Using an image analysis computer application, the pre- and postoperative images were stored and superimposed, and then the amount of material removed from the preoperative inner and outer curved walls was measured at five levels in the apical 5 mm of the canal. The time required for canal preparation, including irrigation, and the time taken to change instruments was recorded. At 1 mm from the apical end, the directions of canal transportation were most frequently toward the outer aspect of the curvature, with the only exception being the canals shaped by the balanced force technique in which more was removed from the inner aspect. The balanced force technique required more preparation time than the rotary instrumentation.