In Vitro Evaluation of Bond Strength to Dentin of Two Post Systems: Computer-aided Design and Computer-aided Manufacturing Fiber Posts vs Splendor Single Adjustable Post.

AIM: To assess dentin-post bond strength and mode of failure through tensile strength testing of two endodontic post systems: CAD/CAM custom-milled fiber posts vs Splendor SAP. MATERIALS AND METHODS: Thirty extracted single-rooted mandibular premolars were sectioned 2 mm coronal to the cementoenamel junction. Root length was standardized at 15 mm, and the root canals were instrumented with #20 K-files followed by 30/0.03 and 30/0.05 ProDesign Logic rotary files, under irrigation with 2.5% NaOCl, and then submitted to final irrigation with 17% EDTA. Canals were filled with gutta-percha and AH PLUS sealer. After 24 hours, the teeth were prepared for post placement to a depth of 10 mm and randomly allocated into two experimental groups (n = 15): CAD/CAM (CC) and Splendor SAP (SS). All posts were cemented with RelyX U200 dual-cure self-adhesive resin cement. The roots were embedded in acrylic resin, and the specimens were stored for 7 days in moist heat (37°C). Tensile strength testing until failure was then performed in a universal testing machine using a crosshead speed of 0.5 mm/minute. The final failure load was tabulated for statistical analysis, and the G test was used to compare the failure modes observed under light microscopy (5× magnification). RESULTS: There was no significant difference between groups regarding tensile bond strength to root dentin (p = 0.325). Conversely, failure mode differed significantly between groups (p = 0.037). CONCLUSION: The tensile bond strength observed for the CAD/CAM and Splendor SAP post systems was similar. Adhesive failure was predominant in both groups; however, the CAD/CAM custom-milled fiber posts failed predominantly at the dentin-resin cement interface, whereas Splendor SAP posts failed mostly at the post-resin cement interface. CLINICAL SIGNIFICANCE: A strong post-dentin bond is a key to the success of dental restorations and prosthetic rehabilitation. In teeth with severe coronal decay and wide canals, both of the tested systems would be able to achieve good cervical fit.

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.

Single-session use of mineral trioxide aggregate as an apical barrier in a case of external root resorption.

External root resorption may occur as a consequence of trauma, orthodontic treatment, bacterial infection or incomplete sealing of the root canal system (bacterial re-infection), and lead to crater formation on the resorbed apex. This would deform the root apex surface, and cause loss of apical constriction. Depending on the extent of the resorptive process, different treatment regimens have been proposed. A 34-year-old male patient presented with an intra-radicular retainer and an inadequate filling on tooth #21, as well as a radiographic image suggesting periapical bone rarefaction. After root canal retreatment, the defect was accessed coronally. The resorption area was chemo-mechanically debrided and since the apical end was very wide, a calcium sulphate matrix was made. Mineral trioxide aggregate (MTA) was used to fill the resorptive defect, and the coronal access was temporarily sealed. After 24 h, the quality of the apical seal was evaluated with the aid of an operating microscope, and then the root canal system was filled. A 12-month follow-up radiograph showed adequate repair of the resorption. Clinically, the tooth was asymptomatic. We concluded that MTA can be successfully used to avoid overextension of the filling material when treating a tooth with external resorption.