Effect of bioceramic root canal sealers on the bond strength of fiber posts cemented with resin cements

Abstract This study aimed to evaluate the influence of calcium silicate-based sealers on the bond strength of fiber posts using conventional and self-adhesive resin cement. Sixty single-rooted teeth were selected. The canals were prepared with a reciprocating instrument 40.06. The roots were randomly distributed in six groups (n = 10) according to the strategies for root canal filling and fiber posts cementation: AH Plus/RelyX ARC; AH Plus/RelyX U200; Bio C Sealer/RelyX ARC; Bio C Sealer/RealyX U200; Sealer Plus BC/RelyX ARC; and Sealer Plus BC/RelyX U200. The roots were transversally sectioned, and one slice per post-third was obtained. The push-out test was performed at a crosshead speed of 1mm/min. The failure patterns were described after assessment with a stereomicroscope with a 10× magnification. Bond strength was calculated and analyzed using the ANOVA and Tukey test. AH Plus did not influence the bond strength of fiber posts cemented with conventional (RelyX ARC) or with self-adhesive resin cement (RelyX U200). The lowest bond strength values were obtained when calcium silicate-based sealers were associated with conventional resin cement (Bio C Sealer/RelyX ARC and Sealer Plus BC/RelyX ARC). Except for Sealer Plus BC/RelyX ARC, all groups presented lower bond strength at the apical portion compared to the cervical portion of the post. Adhesive failures between cement and post and cement and dentin were predominant (55.3%). Calcium silicate-based sealers decreased the bond strength of fiber posts cemented with conventional resin cement.

Resumo Este estudo teve como objetivo avaliar a influência de cimentos à base de silicato de cálcio na resistência de união de pinos de fibra utilizando cimentos resinosos convencionais e autoadesivos. Sessenta dentes humanos monorradiculares foram selecionados. Os canais foram preparados um instrumento reciprocante 40.06. As raízes foram distribuídas aleatoriamente em seis grupos (n = 10) de acordo com as estratégias de obturação do canal e cimentação dos pinos de fibra: AH Plus/RelyX ARC; AH Plus/RelyX U200; Bio C Sealer/RelyX ARC; Bio C Sealer/RealyX U200; Sealer Plus BC/RelyX ARC; e Sealer Plus BC/RelyX U200. As raízes foram seccionadas transversalmente e foi obtido um espécime por terço. O teste de push-out foi realizado em uma velocidade de 1mm/min. Os padrões de falha foram descritos após avaliação em estereomicroscópio com aumento de 10×. A resistência de união foi calculada e analisada por ANOVA e teste de Tukey. AH Plus não influenciou na resistência de união dos pinos de fibra cimentados com cimento resinoso convencional (RelyX ARC) ou autoadesivo (RelyX U200) (p > 0,05). Os menores valores de resistência de união foram obtidos quando os cimentos à base de silicato de cálcio foram associados ao cimento resinoso convencional (Bio C Sealer/RelyX ARC e Sealer Plus BC/RelyX ARC) (p < 0,05). Com exceção do Sealer Plus BC/RelyX ARC, todos os grupos apresentaram menor resistência de união na porção apical em comparação com a porção cervical do pino (p < 0,05). Falhas adesivas entre cimento e pino e cimento e dentina foram predominantes (55,3%). Cimentos a base de silicato de cálcio diminuíram a resistência de união de pinos de fibra cimentados com cimento resinoso convencional.

Evaluation of the dentinal tubule penetration of an endodontic bioceramic sealer after three final irrigation protocols

Introduction: This study aimed to evaluate the dentinal tubule penetration of an endodontic bioceramic sealer, Sealer Plus BC, after three final irrigation protocols. Methods: Thirty distobuccal roots of maxillary molars were selected. Root canal preparation was performed up to an #40.06 instrument (X1 Blue) under 2.5% sodium hypochlorite irrigation. Specimens were randomly divided into three groups (n=10), according to the final irrigation protocol: G-NaOCl (2.5% sodium hypochlorite + PUI), G-SS (0.9% saline solution + PUI) and G-H20 (Deionized water + PUI). After final irrigation protocols, all specimens were irrigated with phosphate buffer solution. Root canal obturation was performed using the single cone technique and Sealer Plus BC, stained with a specific fluorophore. Specimens were transversely sectioned and each root third was evaluated in a confocal scanning laser microscopy. Images obtained were analyzed for sealer penetration in the dentinal tubules. Results: Dentinal tubule penetration of Sealer Plus BC was not observed in any root third, regardless of the final irrigation protocol investigated. Conclusions: Sealer Plus BC dentinal tubule penetration was not observed after none of the protocols tested. Dentinal tubule penetrability of Sealer Plus BC may be related to other factors rather than the final irrigation protocol.

Antibacterial Activity of a New Ready-To-Use Calcium Silicate-Based Sealer

Abstract The aim of this study was to evaluate the antibacterial potential of a calcium silicate-based sealer (Bio-C Sealer, Angelus) against common bacteria in primary and secondary endodontic infections. Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus mutans were exposed to fresh Bio-C Sealer for 24 h by the agar diffusion method (n=5). Additionally, the antibacterial activity was investigated against E. faecalis and S. mutans biofilms (48 h old) grown in discs with 4 mm in diameter and 2 mm in height. (n=3) of set discs of Bio-C Sealer (Angelus), EndoFill (Dentsply-Mallefer), Sealer 26 (Dentsply), AH Plus (Dentsply), Sealapex (Sybron-Endo) and EndoSequence BC Sealer (Brasseler). The antibacterial activity was evaluated by colony forming unity (CFU) counting using ImageJ software. Data were compared by one-way ANOVA followed by Holm-Sidak test (a=5%). Fresh Bio-C Sealer exhibited antimicrobial activity against all bacteria evaluated by agar diffusion method, except for S. mutans. Set discs of all endodontic sealers tested showed similar CFU values for E. faecalis (p>0.05). S. mutans in biofilms showed higher susceptibility to EndoFill compared with the other sealers (p<0.05). In conclusion, the results indicate that fresh Bio-C Sealer does not inhibit S. mutans growth, but exhibits antibacterial activity against E. faecalis, S. aureus, P. aeruginosa and E. coli. After setting, the Bio-C Sealer exhibits an antimicrobial potential comparable to that of the other sealers evaluated in E. faecalis biofilm, but lower than that of EndoFill for S. mutans biofilm.

Resumo O objetivo deste estudo foi avaliar o potencial antibacteriano do novo cimento biocerâmico (Bio-C Sealer, Angelus) contra bactérias comuns em infecções endodônticas primárias e secundárias. Culturas de Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus e Streptococcus mutans foram expostos a amostras frescas do Bio-C sealer durante 24 h pelo método de difusão em agar (n=5). A atividade antibacteriana de amostras dos cimentos Bio-C Sealer (Angelus), EndoFill (Dentsply-Mallefer), Sealer 26 (Dentsply), AH Plus (Dentsply), Sealapex (Sybron-Endo) e EndoSequence BC Sealer (Brasseler) após a presa também foi investigada em biofilmes de 48 h das bactérias E. faecalis e S. mutans, crescidos em discos com 4 mm de diâmetro e 2 mm de altura. A atividade antibacteriana foi avaliada por contagem das unidades formadoras de colônias (UFC) utilizando o software ImageJ. Os dados foram comparados por ANOVA a um critério seguido pelo pós-teste Holm-Sidak (a=5%). Amostras frescas do Bio-C Sealer exibiram atividade antimicrobiana contra todas as bactérias avaliadas pelo método de difusão em ágar, exceto para S. mutans. A análise da formação de biofilme mostrou que todos os cimentos endodônticos testados apresentaram valores similares de UFC para E. faecalis (p> 0,05), enquanto biofilmes de S. mutans foram mais suscetíveis ao EndoFill em comparação com os demais cimentos (p<0,05). Conclui-se que o cimento Bio-C Sealer fresco exibe atividade antibacteriana para E. faecalis, S. aureus, P. aeruginosa e E. coli, mas não inibe o crescimento de S. mutans. Após a presa, o cimento Bio-C Sealer exibe potencial antimicrobiano similar ao dos demais cimentos avaliados em biofilme de E. faecalis, mas inferior ao do EndoFill para S. mutans.

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.