Influência da termoplastificação na resistência ao deslocamento de diferentes materiais resinosos de obturação

Objetivo: O presente estudo tem o objetivo de avaliar, através de push-out, a resistência ao deslocamento dos sistemas de obturação de canais radiculares Resilon/Epiphany e Guta-percha/AH Plus, utilizando as técnicas de condensação lateral e de híbrida de Tagger para obturação, após 6 meses de armazenamento. Materiais e métodos: Um total de 40 dentes humanos monorradiculares extraídos foram preparados através da técnica coroa-ápice. Realizou-se irrigação com NaOCl 1% a cada troca de instrumento e irrigação final com EDTA 17% e soro fisiológico. As amostras foram divididas aleatoriamente, em quatro grupos, de acordo com o material obturador (guta-percha/AH Plus e Resilon/Epiphany) e a técnica obturadora utilizada (Técnica híbrida de Tagger e condensação lateral). Os dentes ficaram armazenados a 37°C e 100% de umidade por 6 meses. Após foram feitas fatias transversais de cada dente e realizado o ensaio de push-out. A análise estatística utilizada foi o teste ANOVA de duas vias (material obturador e técnica de obturação) seguido do teste de comparações de Student-Neuman-Keuls. Resultados: Não houve diferença estatística entre os materiais obturadores quando utilizado a técnica da condensação lateral (p= 0,843) ou a técnica híbrida de Tagger (p=0.225). Quando foi utilizado o sistema Resilon/Epiphany, houve diferença estatisticamente significante entre as técnicas utilizadas (p=0,016). Conclusão: Através do teste de push-out e após 6 meses de armazenamento, os materiais apresentaram comportamento semelhante, no entanto, quando se utilizou a técnica de termoplastificação, o sistema Resilon/Epiphany apresentou resultados inferiores de resistência ao deslocamento.Aim: To evaluate, through push-out test, the bond strengths of different root canal filling systems Resilon/Epiphany and Gutta-percha/AH Plus, using lateral condensation and hybrid Tagger techniques for filling, after 6 months of storage. Methodology: A total of 40 human single-rooted extracted teeth were used and prepared with crown-down technique. Irrigation was performed with 1% NaOCl between each instrument, the smear layer was removed after instrumentation with 17% EDTA, and a final irrigation with saline. The samples were randomly divided, in 4 groups, according to the filling material (gutta-percha/AH Plus and Resilon/Epiphany) and technique (lateral condensation and hybrid Tagger technique) used. The teeth were storage for 6 months at 37°C and 100% humidity. Serial root slices were realized and push-out tests on the filling material were executed. Two-way analysis of variance (ANOVA) (material and technique of filling), following of Student-Newman-Keuls test, were used to assess the results. Results: The push-out test related a significant difference only in Resilon/Epiphany group for filling technique (p=0.016). However, between the root canal filling materials, statistical significant differences were not found to lateral condensation technique (p= 0,843) or to hybrid Tagger technique (p=0.225). Conclusion: Through push-out test and 6 months of storage, the root canal filling materials showed a similar behavior. Nevertheless, when were used the thermoplastification technique, the Resilon/Epiphany combination exhibited lower

Apically extruded debris in filling removal of curved canals using 3 NiTi systems and hand files

The aim of this study was to assess the amount of apically extruded debris during filling removal with WaveOne Gold (WOG), ProTaper Universal Retreatment (PTR), D-RaCe Retreatment (DRR) or hand files (HF), to compare the working time during filling removal, and to describe failures of NiTi instruments. Forty mesiobuccal roots of maxillary first molars were prepared with WOG Primary, obturated and divided into 4 groups (n=10), according to the instruments used: WOG, PTR, DRR or HF. Distilled water was used as irrigant and the extruded debris were collected in Eppendorf tubes and dried. The amount of extruded debris was determined by subtracting the final from the initial weight. The time of filling removal for each canal was recorded and the instruments used were analyzed pre and post-operatively by SEM. Kruskal-Wallis and Dunn’s test analyzed extruded debris data and ANOVA, followed by Tukey’s test, compared the working time data (α=0.05). Instrument deformation and fracture were described. WOG produced significantly less debris compared with HF and DRR (p0.05). HF, PTR and DRR showed no significant difference (p>0.05). Working time in HF group was significantly higher than others (p<0.05). SEM analyses showed, from the 18 instruments evaluated, 3 fractures and 10 deformations. All instruments tested caused debris extrusion. WOG was associated with less extrusion than DRR and HF. Filling removal with HF was slower than with the other instruments. All NiTi systems presented fracture and deformation

Centering and transportation: in vitro evaluation of continuous and reciprocating systems in curved root canals

One of the goals of endodontic therapy is the shaping and cleaning of the root canal system. In recent years, there has been multiple systems instrumentation, and changes in their dynamics are central to maintain the original shape of the canal after preparation. Aims: The aim of this study was to evaluate centering and transportation in curved root canals after using ProTaper® and MTwo® in continuous rotation, Reciproc® in reciprocating motion, and a step-down manual instrumentation technique. Settings and Design: Mesiobuccal roots of human extracted the first and second maxillary molars were selected and the canals (n = 60) were divided into four groups according to the preparation techniques: PT-ProTaper®; MT-MTwo®; RE-Reciproc®; MI-manual instrumentation. Subjects and Methods: The final apical diameter was standardized to a size 25. Centering and transportation were evaluated by cone-beam computed tomography and Adobe Photoshop 8.0 software. Statistical Analysis Used: The data were statistically analyzed by ANOVA and Tukey post hoc. Results: Results of transportation showed no statistical differences (P > 0.05) between groups, and significantly, difference (P < 0.05) between ProTaper® and Reciproc® was found when evaluating centering ability in the apical third. Conclusions: We concluded that there were no differences in transportation between the evaluated systems for the preparation of curved root canals with an apical instrumentation diameter of #25. For centering ability, in the apical third, ProTaper® presented worst behavior when compared to Reciproc®

Centering and transportation: in vitro evaluation of continuous and reciprocating systems in curved root canals

Context:One of the goals of endodontic therapy is the shaping and cleaning of the root canal system. In recent years, there has been multiple systems instrumentation, and changes in their dynamics are central to maintain the original shape of the canal after preparation. Aims: The aim of this study was to evaluate centering and transportation in curved root canals after using ProTaper® and MTwo® in continuous rotation, Reciproc® in reciprocating motion, and a step-down manual instrumentation technique. Settings and design: Mesiobuccal roots of human extracted the first and second maxillary molars were selected and the canals (n = 60) were divided into four groups according to the preparation techniques: PT-ProTaper®; MT-MTwo®; RE-Reciproc®; MI-manual instrumentation.Subjects and Methods: The final apical diameter was standardized to a size 25. Centering and transportation were evaluated by cone-beam computed tomography and Adobe Photoshop 8.0 software.Statistical Analysis Used: The data were statistically analyzed by ANOVA and Tukey post hoc. Results: Results of transportation showed no statistical differences (P > 0.05) between groups, and significantly, difference (P 0.05) between groups, and significantly, difference (P 0.05) between groups, and significantly, difference (P 0.05) between groups, and significantly, difference (P < 0.05) between ProTaper® and Reciproc® was found when evaluating centering ability in the apical third. Conclusions: We concluded that there were no differences in transportation between the evaluated systems for the preparation of curved root canals with an apical instrumentation diameter of #25. For centering ability, in the apical third, ProTaper® presented worst behavior when compared to Reciproc

Curved canal morphological changes after over instrumentation and apical foramen shaping with R-Pilot®, ProDesign Logic® and ProGlider®

Aim: To evaluate the apical canal morphological change, centering ability, and apical trans-portation of curved canals after foraminal enlargement 1 mm beyond the apex with different instruments and after apical foramen shaping. Methodology: Thirty-three mesiobuccal molars’ canals with curvatures between 25 and 35 and a radius of less than 10 mm were selected and divided according to the instrument used 1 mm beyond the apical foramen: R-Pilot #12.5/.04(RPG), ProDesign Logic #25/.01(PDG), and ProGlider #16/.02(PGG). After over instrumentation, #25/.05 ProDesign Logic prepared the canals until the apical foramen. Micro-CT scans obtained before instrumentation (time point 1), after instruments use 1 mm beyond foramen (time point 2) and after final prepa-ration (time point 3) were used to evaluate apical canal morphological changes according to the area, the ratio of Feret’s diameters and circularity, transportation and centering. Data were analyzed by parametrical or non-parametrical tests (α=0.05). Results: PDG increased the apical foramen area from time point 1 to 3 (P=0.03). There were no differences in the ratio of Feret’s diameters or circularity (P>.05). In all groups, apical transportation was in mesial direction and increased after final preparation in RPG (P=0.01). Instrument centering ability was better at time point 3 than 2 in PDG (P=0.01), and PDG presented better centering than RPG at time point 3 (P=0.02). Conclusion: Instruments used 1 mm beyond the apical foramen combined with #25/.05 final preparation did not lead to apical canal morphological change. ProDesign Logic #25/.01 followed by #25/.05 improved centering without increasing transportation in root canals

Validation of self-reported history of root canal treatment in a southern Brazilian subpopulation

The aim of this study was to assess self-reported history of root canal treatment (SRHRCT) as a method for detecting the presence of root canal treatment (RCT) and apical periodontitis (AP) in a southern Brazilian subpopulation. In this cross-sectional study, 136 military police officers from the city of Porto Alegre, Brazil, were included. The participants were interviewed and full-mouth periapical radiographs were taken. A calibrated examiner determined the presence of RCT and AP by applying standardized criteria. The diagnostic accuracy of SRHRCT was calculated separately for RCT and AP. Accuracy, sensitivity, specificity, positive and negative predictive values (+PV and -PV), efficiency, and positive and negative likelihood ratios (+LR and -LR) were estimated. The mean age of the participants was 34.1 ± 10.4 years and 88.2% were males. Overall, SRHRCT demonstrated high sensitivity and specificity for RCT, but not for AP: sensitivity (RCT = 0.960, AP = 0.757) and specificity (RCT = 0.835, AP = 0.631). The estimated values for PV and LR were: +PV (RCT=0.777, AP=0.396), -PV (RCT = 0.972, AP = 0.890), +LR (RCT = 5.853, AP = 2.057), and -LR (RCT = 0.046, AP = 0.383). SRHRCT proved to be a good predictor of the presence of RCT, but a weak predictor of AP in this subpopulation

Influência da termoplastificação na resistência ao deslocamento de diferentes materiais resinosos de obturação

Objetivo: O presente estudo tem o objetivo de avaliar, através de push-out, a resistência ao deslocamento dos sistemas de obturação de canais radiculares Resilon/Epiphany e Guta-percha/AH Plus, utilizando as técnicas de condensação lateral e de híbrida de Tagger para obturação, após 6 meses de armazenamento. Materiais e métodos: Um total de 40 dentes humanos monorradiculares extraídos foram preparados através da técnica coroa-ápice. Realizou-se irrigação com NaOCl 1% a cada troca de instrumento e irrigação final com EDTA 17% e soro fisiológico. As amostras foram divididas aleatoriamente, em quatro grupos, de acordo com o material obturador (guta-percha/AH Plus e Resilon/Epiphany) e a técnica obturadora utilizada (Técnica híbrida de Tagger e condensação lateral). Os dentes ficaram armazenados a 37°C e 100% de umidade por 6 meses. Após foram feitas fatias transversais de cada dente e realizado o ensaio de push-out. A análise estatística utilizada foi o teste ANOVA de duas vias (material obturador e técnica de obturação) seguido do teste de comparações de Student-Neuman-Keuls. Resultados: Não houve diferença estatística entre os materiais obturadores quando utilizado a técnica da condensação lateral (p= 0,843) ou a técnica híbrida de Tagger (p=0.225). Quando foi utilizado o sistema Resilon/Epiphany, houve diferença estatisticamente significante entre as técnicas utilizadas (p=0,016). Conclusão: Através do teste de push-out e após 6 meses de armazenamento, os materiais apresentaram comportamento semelhante, no entanto, quando se utilizou a técnica de termoplastificação, o sistema Resilon/Epiphany apresentou resultados inferiores de resistência ao deslocamento.Aim: To evaluate, through push-out test, the bond strengths of different root canal filling systems Resilon/Epiphany and Gutta-percha/AH Plus, using lateral condensation and hybrid Tagger techniques for filling, after 6 months of storage. Methodology: A total of 40 human single-rooted extracted teeth were used and prepared with crown-down technique. Irrigation was performed with 1% NaOCl between each instrument, the smear layer was removed after instrumentation with 17% EDTA, and a final irrigation with saline. The samples were randomly divided, in 4 groups, according to the filling material (gutta-percha/AH Plus and Resilon/Epiphany) and technique (lateral condensation and hybrid Tagger technique) used. The teeth were storage for 6 months at 37°C and 100% humidity. Serial root slices were realized and push-out tests on the filling material were executed. Two-way analysis of variance (ANOVA) (material and technique of filling), following of Student-Newman-Keuls test, were used to assess the results. Results: The push-out test related a significant difference only in Resilon/Epiphany group for filling technique (p=0.016). However, between the root canal filling materials, statistical significant differences were not found to lateral condensation technique (p= 0,843) or to hybrid Tagger technique (p=0.225). Conclusion: Through push-out test and 6 months of storage, the root canal filling materials showed a similar behavior. Nevertheless, when were used the thermoplastification technique, the Resilon/Epiphany combination exhibited lower

In vitro comparative study of NITi systems using reciprocating, continuous and an association of motions in curved root canals

O preparo químico-mecânico tem sido essencial no sucesso do tratamento endodôntico. No entanto, atualmente não existe instrumento ou técnica com capacidade de proporcionar a limpeza e a desinfecção dos sistemas de canais em sua totalidade. O objetivo desse estudo foi avaliar a limpeza, tempo, transporte e centralização de preparos de canais radiculares curvos utilizando os sistemas de rotação contínua ProTaper®, de rotação alternada WaveOne® e uma sugestão de técnica híbrida de preparo. Foram selecionadas raízes mesiais de primeiros molares inferiores humanos permanentes extraídos. Após a definição dos ângulos de curvatura e raio, os canais (n=60) foram divididos em três grupos experimentais, conforme sistemas de preparo (ProTaper, WaveOne, WaveOne Técnica Híbrida). O diâmetro apical final foi padronizado em #25. As quantidades de debris e smear layer remanescentes foram analisadas em microscopia eletrônica de varredura, através de escores, e avaliadas estatisticamente por meio do teste de Kruskal–Wallis. Fraturas ou deformações nos instrumentos foram registradas. O tempo de preparo foi cronometrado e analisado através de ANOVA e Tukey. Tomografia computadorizada de feixe cônico pré e pós-operatória foram feitas para mensuração do transporte e centralização dos canais e os resultados obtidos foram avaliados estatisticamente através de ANOVA. Em relação à capacidade de limpeza, os três grupos apresentaram semelhante capacidade em remover debris e formar smear layer, sem diferenças estatísticas (P>0,05) em todas as porções dos canais. O preparo com apenas um instrumento foi significativamente mais rápido do que com sequências de instrumentos (P 0.05). Instrumentation with WaveOne was significantly faster than with other instruments (P< 0.05). During preparation, no file fractured, three suffered deformations. No difference in the transportation and centering ratio was found between the systems. Under the conditions of this study, all instruments maintained the original canal curvature well and were safe to use. A single-file system presented as good cleanliness capacity as others, reducing the preparation time significantly, although none could provide a complete debridement