Eficácia de três protocolos de irrigação final para remoção de raspas dentinárias e material obturador em irregularidades simuladas / Effectiveness of three final irrigation protocols for debris and filling removal from simulated irregularities

Objetivos: Avaliar três protocolos de irrigação final para remoção de detritos e material obturador de istmos simulados. Métodos: Setenta e oito pré-molares foram preparados com o sistema WaveOne Gold 45.05. Os dentes foram seccionados longitudinalmente e um istmo padronizado foi confeccionado no terço apical. Seis raízes foram utilizadas como controle negativo. Os espécimes foram randomizados em dois grupos principais (n=36). Trinta e seis raízes tiveram o istmo preenchido com detritos e as outras trinta e seis raízes foram obturadas com guta-percha e cimento endodôntico, por meio da técnica híbrida de Tagger. Cada grupo foi dividido em três subgrupos (n=12), de acordo com o protocolo de irrigação final: Easy Clean; irrigação ultrassônica passiva (PUI); e XP Clean. A ativação do NaOCl 2,5% pelo Easy Clean foi realizada em três ciclos de vinte segundos; e pelo XP Clean, por um minuto em movimento reciprocante e contínuo, respectivamente. No grupo PUI, o irrigante foi ativado em três períodos de vinte segundos. Resultados: Não foi encontrada associação entre os escores de remoção de detritos e os protocolos de irrigação (p=0,165). Foi observada associação entre os escores de remoção do material obturador e os protocolos de irrigação final (p<0,05). Conclusões: Os protocolos de irrigação final foram efetivos para a remoção de detritos, mas não para remoção de material obturador de istmos no terço apical (AU).

This study aimed to assess three final irrigation protocols on debris and filling removal from simulated irregularities. Methods: Seventy-eight mandibular premolars were prepared with WaveOne Gold system 45.05, splitted longitudinally, and a standardized groove was performed in the apical portion of the canals. Six roots served as negative control. The roots were randomly divided into two main groups (n = 36). The grooves were filled with dentin debris in thirty six roots. The others thirty-six were filled with gutta-percha and endodontic sealer using Tagger hybrid technique. Each main group was then divided into three groups (n = 12) according to the final irrigation protocol: Easy Clean, passive ultrasonic irrigation (PUI), and XP Clean. In Easy Clean 2.5% NaOCl activation was performed for 3 cycles of 20 seconds and XP Clean for one minute under reciprocating and continuous rotary motion and continuous rotary motion, respectively. In the PUI group, the irrigant was activated in three periods of 20 seconds. Results: No association was found among the scores of debris removal and the irrigation protocols (p = .165). An association was observed among the filling material removal scores and irrigation protocols (p< .05). Conclusion: Easy Clean, PUI and XP Clean were effective for dentin debris removal, but did not for filling material from artificial grooves in the apical third (AU).

Evaluation of physicochemical properties of new calcium silicate-based sealer

Abstract This study aimed to evaluate the physicochemical properties of a calcium silicate-based sealer (Sealer Plus BC; MK Life, Porto Alegre, Brazil) compared with an epoxy-resin sealer (AH Plus; Dentsply DeTrey GmbH, Konstanz, Germany). Initial and final setting time was assessed based on ISO 6876:2012 and ASTM C266:03. Calcium ion release and pH were evaluated by filling polyethylene tubes with sealers and then immersing them in 10 mL of deionized water. Following experimental periods of 1, 24, 72 and 168 hours, the samples were measured regarding pH and calcium ion release with a pH meter and a colorimetric spectrophotometer, respectively. The flow was examined based on ISO 6876:2012. Rings of 10 mm in diameter with 1 mm thickness were prepared to analyze the radiopacity (ISO 6876:2012 and ADA n.57) and solubility (ISO 6876:2012). The data were analyzed by variance analysis, Student-T and Tukey tests (p<0.05). The calcium ion release and pH values were significantly higher for the Sealer Plus BC compared with the AH Plus (p<0.05). Lower setting time, flow and radiopacity were observed for the bioceramic sealer than for AH Plus (p<0.05). Sealer Plus BC exhibited higher solubility compared with AH Plus (p<0.05). Sealer Plus BC showed physicochemical properties as setting time, pH, calcium release, flow, and radiopacity following the required standards, but higher solubility than the minimum values required by ISO 6876:2012.

Resumo Este estudo teve por objetivo avaliar as propriedades físico-químicas de um cimento à base de silicato de cálcio (Sealer Plus BC MK Life, Porto Alegre, Brasil) e compará-las a um cimento à base de resina epóxica (AH Plus, Dentsply DeTrey GmbH, Konstanz, Alemanha). Tempo de presa inicial e final foram avaliados com base na ISO 6876:2012 e ASTM C266:03. Liberação de íons cálcio e pH foram avaliados após o preenchimento de tubos de polietileno com os cimentos e imersão em 10 mL de água deionizada. Após os tempos experimentais de 1,24,72 e 168 horas, os valores de pH e liberação de íons cálcio foram mensurados utilizando um medidor de pH e um espectofotômetro colorimétrico, respectivamente. Escoamento foi avaliado com base na ISO 6876:2012. Moldes de 10 mm de diâmetro e 1 mm de espessura foram preparados para análise de radiopacidade (ISO 6876:2012 e ADA n.57), solubilidade (ISO 6876:2012). Os dados foram analisados por análise de variância, teste T de Student e teste de Tukey (p<0,05). A liberação de íons cálcio e os valores de pH foram significativamente maiores para o Sealer Plus BC em comparação com o AH Plus (p<0,05). Menores valores de tempo de presa, escoamento e radiopacidade foram observados para o cimento biocerâmico quando comparados com o AH Plus (p<0,05). Sealer Plus BC apresentou propriedades físico-químicas de tempo de presa, pH, liberação de íons cálcio, escoamento, radiopacidade de acordo com as normas exigidas, porém maior solubilidade que aquelas previstas pela ISO 6876:2012.

Microbiological analysis of absorbent paper points employed by undergraduate students from a dental school in south of Brazil

Aim: The aim of this study was identify contamination on absorbent paper points used by students of Dental Clinic III of the Faculty of Dentistry of Federal University of Rio Grande do Sul in the semester 2015/1, in order to warn students and professionals of the area on the importance to sterilize these materials. Material and Methods: In a clinical environment, 180 absorbent paper points we collected (80 of them from the first series and 80 from the second one), from 40 students. After the collection, each one was singly immersed in a microtube containing 1.5 ml of the BHI (Brain Heart Infusion) culture. Positive control was composed by one paper point contaminated by saliva, and negative control was composed by a closed microtube, only with BHI. The microtubes were incubated at 37ºC in bacteriological incubator during 14 days. The microtubes that presented turbidity were considered positive, and those which did not present turbidity were considered negative. Results: The results were analyzed by the Fisher Exact Test, which demonstrated that paper points from the second series presented higher agreement contamination between the paper points collected from each box, when compared to the analyzed boxes from the first series (p=0.03). All the samples observed presented growth of Bacillus spp in the microorganism identification. Conclusions: It is possible conclude that absorbing paper points, when exposed to clinical environment suffer contamination, and the autoclave sterilization is necessary before the use, regardless the commercial brand, in order to ensure the aseptic chain maintenance.

Apical Extrusion of Debris and Irrigants Using Different Irrigation Needles

Abstract This study evaluated the influence of irrigation tip, root canal curvature and final apical diameter on periapical debris and irrigant extrusion during root canal instrumentation. After being classified as mildly or moderately curved, the mesiobuccal root canals of 90 human molars were instrumented. The teeth were allocated into three groups according to the used needle type: a flat open-end needle (Group 1), a side-vented needle (Group 2) or a double side-vented needle (Group 3). The amount of extruded material after instrumentation was calculated for each group. The differences in irrigant and debris extrusion between the experimental groups were analyzed with the Mann-Whitney U test. Irrigation tips and final instrument diameter differences were analyzed with the Kruskal-Wallis test. Multiple groups were compared using the Mann-Whitney U-test with a Bonferroni correction at α=0.05. The amount of extruded material from the double side-vented needle was significantly less than the open-ended flat needle (p=0.008), but there was no difference compared to the side-vented needle (p=0.929). The results showed no effect of root curvature and final apical diameter on the amount of irrigant and debris extrusion (p>0.05). The double side-vented needles generated the least material extrusion to the periapical tissues. Irrigation needle type had the greatest influence on periapical irrigant and debris extrusion and the double side-vented needles may be safely used during endodontic therapy.

Resumo Este estudo avaliou a influência do tipo de agulha de irrigação, curvatura do canal radicular e diâmetro apical final sobre a extrusão de detritos e solução irrigadora durante o preparo físico-químico do canal radicular. O canal mésio- vestibular de 90 molares foi instrumentado, após ser classificado como de curvatura leve ou moderada. Os dentes foram divididos de acordo com o tipo de agulha utilizada em 3 grupos: agulha de extremidade aberta (Grupo 1), agulha de extremidade fechada com abertura lateral (Grupo 2) ou agulha de extremidade fechada com dupla abertura lateral (Grupo 3). A quantidade de material extruído após a instrumentação foi calculada em cada grupo. As diferenças de extrusão de solução irrigadora e detritos entre os grupos experimentais foram analisados com o teste de Mann-Whitney. As diferenças entre o tipo de agulha de irrigação e o diâmetro apical final foram analisados com o teste de Kruskal-Wallis. Grupos múltiplos foram comparados usando o teste U de Mann-Whitney com correção de Bonferroni em α= 0,05. A quantidade de material extruído pela agulha de extremidade fechada com dupla abertura lateral foi significativamente menor do que a agulha de extremidade aberta (p = 0,008), porém não houve diferença em relação a agulha de extremidade fechada com abertura lateral (p = 0,929). Os resultados não indicaram relação entre a curvatura radicular e o diâmetro apical final sobre a quantidade de solução irrigante e detritos de extruídos (p> 0,05). O uso de agulhas com dupla abertura lateral resultaram em uma menor extrusão de material aos tecidos periapicais. O tipo de agulha de irrigação teve a maior influência sobre extrusão periapical de solução irrigadora e detritos. As agulhas de extremidade fechada com dupla abertura lateral podem ser utilizadas com segurança durante a terapia endodôntica.