Ultrasonic tips as an auxiliary method for the instrumentation of oval-shaped root canals

Abstract To evaluate the influence of novel ultrasonic tips as an auxiliary method for the rotary preparation of flattened/oval-shaped canals. Forty-five mandibular incisors were selected and divided into one of three experimental groups (n = 15): Group PFCP - ProDesign Logic 25/.05 + Flatsonic + Clearsonic + Prodesign Logic 40/.01; Group FCP - Flatsonic + Clearsonic + ProDesign Logic 40/.01; and Group PP - Prodesign Logic 25/.05 + Prodesign Logic 40/.05. The teeth were scanned preoperatively and postoperatively using microcomputed tomography. The percentage values for increase in volume, non-instrumented surface area, dentin removal, degree of canal transportation, and centering ratio between the experimental groups were examined. Data were analyzed using the non-parametric Kruskal-Wallis and Dunn's tests (p < 0.05). Group PFCP showed the greatest volume increase in the total portion of the root canal and the lowest percentage of non-instrumented surface area. Regarding the degree of transportation in the buccolingual direction, statistically significant differences between groups PFCP and PP were observed at the coronal third of the canal. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. As for the centering ratio, statistically significant differences were found in the buccolingual direction. In the mesiodistal direction, no statistically significant differences were observed at the coronal, middle, and apical thirds. The use of novel ultrasonic tips combined with rotary instruments in group PFCP provided a significant increase in volume and reduced the percentage of non-instrumented areas during the preparation of flattened/oval-shaped canals.

A novel ultrasonic tip for removal of filling material in flattened/oval-shaped root canals: a microCT study

Abstract The aim of this study was to evaluate the influence of a novel ultrasonic tip as an auxiliary method for removing filling material from flattened/oval-shaped canals. The null hypothesis tested was that this method does not influence removing the filling material in flattened/oval-shaped canals. Forty-five mandibular incisors were selected and randomly divided into three experimental groups (n = 15) according to different protocols for removing root canal filling material. Group R: Reciproc R25/.08, Group RC: Reciproc R25/.08 + Clearsonic tip, and Group CR: Clearsonic tip + Reciproc R25/.08. The teeth were scanned pre and post-operatively by means of a micro-computed tomography system. Data were analyzed using non-parametric Kruskal-Wallis and Dunn tests (p < 0.05). The percentage of residual root canal filling material between the experimental groups was examined. Statistically significant differences between the experimental groups were found in the root canal. Group R had the highest percentage of residual root canal filling material when compared with Groups RC and CR. The lowest percentage of residual root canal filling material was observed in Group CR. In the apical third of the root canal, statistically significant differences were found between the different protocols. The use of the ClearSonic tip followed by the Reciproc 25/.08 file to remove filling material resulted in the lowest percentage of residuals in the whole root canal and in the apical third.

Assessment of the shaping ability of different reciprocating systems in simulated curved root canals using micro-computed tomography / Análise do preparo de canais curvos simulados promovido por sistemas reciprocantes: análise por microtomografia computadorizada

Aim: To analyze the shaping ability of Unicone (Medin), Wave One (Dentsply Maillefer) and Reciproc (VDW) reciprocating systems through the use of micro-computed tomography (MCT) in simulated curved canals. Methods: The shaping time, the centering ability and the changes in canal volumes of these systems were measured. Sixty artificial root canals with a curvature range of 300 in resin blocks, were scanned pre and postoperatively by MCT. The resin blocks were divided into four groups (n=15) and the root canals were shaped using three reciprocating systems and Ni-Ti Flex files (Dentsply Maillefer) for the control group. The data were analized using the software CTAnalyser and the Shapiro-Wilks test with p<0.05 indicating a statistically significant difference. Results: The results showed statistically significant difference (p<0.05) between the reciprocating and manual instruments regarding the shaping time. There was not statistically significant difference between the reciprocating systems used in this study. In the cervical portion of the canal, the Unicone system showed the highest volume increase of the reciprocating systems. No statistically significant differences regarding the centering ability of the reciprocating systems were found. Conclusions: In comparison to the manual preparation technique, the reciprocating instruments provided a faster shaping of the simulated root canals and similar centering ability. Lastly, concerning the volume increase of the root canal portions, statistically significant differences in the cervical portion of the root canals were observed, identifying the highest values for the Unicone group within the reciprocating systems. Lastly, the reciprocating systems provided an adequate centering ability

Objetivos: Analisar por meio do micro tomógrafo computadorizado (MTC), a qualidade do preparo promovido pelos sistemas reciprocantes Unicone (Medin), Wave one (Dentsply Maillefer) e Reciproc (VDW). Material e Métodos: Foi feita uma avaliação da alteração do volume, centralização e tempo de preparo de canais curvos simulados. Foram utilizados sessenta blocos de acrílico com canal artificial com curvatura de 300. Cada espécime foi escaneado 2 vezes (pré e pós-instrumentação) por meio do (MTC). Os blocos foram divididos em 4 grupos (n=15) e os canais foram preparados com os sistemas reciprocantes, sendo o grupo controle preparado com limas NiTi Flex (Dentsply Maillefer). A alteração do volume, centralização e tempo de preparo dos 3 sistemas foram medidos e comparados com os dados obtidos previamente. Os dados foram analisados utilizando o software CTAnalyser e submetidos ao teste de normalidade de Shapiro-Wilks, sendo o nível de significância de 5%. Resultados: Houve diferença estatisticamente significante (P<0.05) entre os instrumentos reciprocantes e os manuais em relação ao tempo dispendido para o preparo. Na porção cervical do canal, o volume promovido pelo sistema Unicone foi maior do que nos outros, sendo o grupo manual significantemente maior em relação a todos os grupos. Não observou-se diferença estatística significante na centralização do preparo entre os sistemas reciprocantes. Conclusão: Em relação à técnica manual, os instrumentos reciprocantes proporcionaram uma agilidade maior no preparo dos canais e apresentaram semelhanças no aumento do volume das porções do canal radicular. Finalmente, os sistemas reciprocantes promoveram um preparo centralizado.

Avaliação do pH, liberação de íons cálcio e atividade antimicrobiana do cimento Portland associado a Bambusa textilis em diferentes proporções / Analysis of pH, calcium ion release and antibacterial activity of Portland cement associated to Bambusa textilis in different proportion

Introdução: há uma busca incessante por agentes fitoterápicos na medicina e odontologia. Dentro da endodontia, busca-se uma substância que potencialize os efeitos biológicos e antimicrobianos do hidróxido de cálcio como curativo de demora. Não há na literatura relatos sobre a associação do cimento Portland com a Bambusa textilis, uma planta nativa da China, onde é usada na elaboração de medicamentos, pois se trata de uma fonte importante de resinas, sendo, portanto utilizadas por seu poder anti-inflamatório, anticatarral, anticonvulsivante e antitérmico. Sabendo da semelhança do cimento Portland com o MTA, e que esse ultimo apresenta bons resultados físico-químicos, surge a dúvida da possibilidade da associação, com a finalidade de melhorar as atividades antimicrobianas, e a interferência na liberação de íons cálcio e hidroxila. Objetivo: avaliar o pH, liberação de íons cálcio e atividade antimicrobiana do cimento Portland associado a Bambusa textilis em diferentes proporções. Metodologia: os cimentos experimentais foram 3 g Cimento Portland + 1,2 ml de Bambusa textilis (G1); 3 g Cimento Portland + 0,6 ml de água + 0,6 de Bambusa textilis (G2); 3 g Cimento Portland + 0,9 ml água + 0,3 ml de Bambusa textilis (G3); 3 g Cimento Portland puro (controle) + 1,2 ml água (G4); Bambusa textilis (controle): 20 microlitros por poço. Para os testes de pH e liberação de íons cálcio foram utilizados tubos de polietileno, os quais foram preenchidos com os cimentos e imersos em frascos contendo água deionizada. As mensurações foram por meio de um peagâmetro e espectrofotômetro de absorção atômica. Para a análise da atividade antimicrobiana, foi utilizada a técnica de difusão radial com cepa de Enterococcus faecalis. Os halos de inibição foram mensurados com auxílio de um paquímetro digital. A análise estatística foi realizada pelo teste ANOVA para comparação global, e teste de Tukey para comparações individuais, com significância de 5%. Resultados: os valores de pH se mostraram próximos ao neutro para todos os grupos em todos os períodos experimentais. Houve liberação de íons cálcio e ocorreu em todos os grupos e em todos os períodos experimentais. Em relação à atividade antimicrobiana, nenhuma das proporções apresentou atividade. Conclusão: a associação da Bambusa textilis ao cimento Portland manteve seu pH e liberação de íons cálcio, mas não potencializou sua atividade antimicrobiana frente ao E. faecalis. (AU)

Introduction: there is a search for phytotherapeutic agents in medicine and dentistry. Within endodontics, a substance that potentiates the biological and antimicrobial effects of calcium hydroxide as a delay dressing is sought. There are no reports in the literature about the association of Portland cement with Bambusa textilis, a plant native to China, where it is used in the manufacture of medicines, since it is an important source of resins and is therefore used for its anti-inflammatory power, anticonvulsive and antipyretic. Knowing the similarity of the Portland cement with the MTA, and that the latter presents good physicochemical results, the possibility of the association arises, with the purpose of improving the antimicrobial activities, and the interference in the release of calcium and hydroxyl ions. Aim: to analyze the pH, calcium ion release and antibacterial activity of Portland cement associated to Bambusa textilis in different proportions. Methods: the experimental cements ́ proportions were: 3 g of Portland cement + 1.2 ml of Bambusa textilis (G1); 3 g of Portland cement + 0.6 ml of water + 0.6 of Bambusa textilis (G2); 3 g of Portland cement + 0.9 ml of water + 0.3 ml of Bambusa textilis (G3); 3 g of pure Portland cement (control group) + 1.2 ml of water (G4); Bambusa textilis (control group): 20 µLper well. Polyethylene tubes filled with the cements and immersed in deionized water were employed. Calcium ion release was analyzed using an atomic absorption spectrophotometer and the change in pH was determined through a pH meter. For the analysis of antibacterial activity, a digital radial diffusion assay with a Enterococcus faecalis strain was utilized. Statistical analysis was performed using ANOVA and Tukey's tests. The level of significance was set at P = 0.05. Results: pH values were close to neutral for all of the experimental groups in all periods evaluated. Calcium ion release was observed in all experimental groups and evaluation periods. Regarding the antibacterial activity, this property could not be detected in any of the proportions used in this study. Conclusions: the association of Bambusa textilis to Portland cement, preserved its pH values and its calcium ion release property. Nevertheless, it did not improve its antibacterial activity against E. faecalis strains. (AU)