Abstract This study evaluated the cytotoxicity, the antimicrobial and physicochemical properties of root canal sealers incorporated with phytotherapic Uncaria tomentosa (UT). Unmodified AH Plus (Dentsply, DeTrey, Germany) and MTA Fillapex (Angelus, Londrina, Brazil) were used as controls. UT was incorporated into AH Plus and MTA Fillapex, at concentrations of 2% and 5% of the total weight of these sealers (w/w). Flowability, setting time, and solubility were evaluated following ISO requirements. The pH values were measured at periods of 12, 24, 48 hours, and 7 days. The antimicrobial activity of the sealers against Enterococcus faecalis was analyzed by both direct contact tests in freshly prepared sealers, and after 7 days. The cytotoxicity of the samples was evaluated by the MTT assay, to check Balb/c 3T3 cell viability. The statistical analysis was performed by one-way ANOVA and Tukey’s test (p < 0.05). The incorporation of UT was associated with a decrease in flow, for both sealers, an increase in AH Plus setting time, increase in MTA Fillapex pH values, and solubility (after 14 days), for both sealers (p < 0.05). Regarding the antibacterial evaluation, bacterial reduction was reported after incorporation of UT into both AH Plus and MTA Fillapex, up to 7 days after handling of the material (P<0.05). UT incorporation decreased the cytotoxic effects of both AH Plus and MTA Fillapex sealers in a way directly proportional to their respective concentrations (p < 0.05). In conclusion, UT can be added to both sealers to reduce their cytotoxicity, and improve their antibacterial effects, without compromising their original physicochemical properties.

Resumo Esse estudo investigou a resistência de união de dois cimentos endodônticos experimentais à base de MTA e butiletilenoglicol dissalicilato: MTAe e MTAe. Os materiais de referência utilizados para comparação foram os cimentos endodônticos MTA Fillapex e AH Plus. Vinte incisivos superiores humanos foram selecionados e um slice dentinário de 1 mm de espessura foi obtido do terço cervical de cada raiz. Na superfície coronária de cada slice, quatro orifícios com 0,9 mm de diâmetro foram confeccionados através da dentina. Uma irrigação padronizada foi realizada e os orifícios foram preenchidos com um dos quatro cimentos endodônticos avaliados: AH Plus, MTA Fillapex, MTAe, e MTAe-HA. Os slices preenchidos foram armazenados em solução PBS (pH 7,2) durante 7 dias a 37°C. O ensaio de push-out foi realizado por meio de um dispositivo com 0,7 mm de diâmetro. A carga foi aplicada com a velocidade de 0,5 mm/min até a obtenção de deslocamento do material obturador. Os resultados foram expressos em MPa. O teste de Kruskal-Wallis foi aplicado para avaliar o efeito da resistência de união de cada cimento endodôntico. O teste de Mann-Whitney com correção de Bonferroni foi utilizado para isolamento das diferenças. O erro do tipo-alfa foi fixado em 0,05. Diferenças significantes entre os valores de medianas obtidos pelos materiais foram observados (p<0,001). O AH Plus demonstrou os maiores valores de resistência de união (p<0,001). Em contraste, o MTA Fillapex apresentou a menor resistência de união entre todos os cimentos testados (p<0,001). Os cimentos experimentais demonstraram valores intermediários, com ausência de diferenças estatísticas entre si (p>0,05). Em conclusão, os cimentos endodônticos experimentais à base de MTA e butiletilenoglicol dissalicilato apresentaram resultados adequados de resistência de união quando comparados ao MTA Fillapex.

Abstract This study investigated the bond strength of two experimental root canal sealers based on MTA and butyl ethylene glycol disalicylate: MTAe and MTAe-HA. The reference materials used for comparison were AH Plus and MTA Fillapex. Twenty human upper incisors were selected and one 1 mm slice was obtained from the cervical third of each root. On the coronal surface of each slice, four 0.9 mm wide holes were drilled through the dentine. Standardized irrigation was performed and holes were filled with one of the four tested sealers: AH Plus, MTA Fillapex, MTAe, and MTAe-HA. The filled slices were stored in a PBS solution (pH 7.2) for 7 days at 37 °C. A push-out assessment was performed with a 0.7 mm plunger tip. Load was applied at a crosshead speed of 0.5 mm/min until sealer displacement. The results were expressed in MPa. The Kruskal-Wallis test was applied to assess the effect of each sealer on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. Significant differences among medians values obtained by materials were observed (p<0.001). AH Plus displayed the highest value of bond strength (p<0.001). In contrast, MTA Fillapex presented the lowest bond strength among all tested sealers (p<0.001). Experimental sealers showed intermediary bond strength values, with no statistical differences between them (p>0.05). In conclusion, experimental root canal sealers presented suitable bond strength outcomes when compared to MTA Fillapex.

Resumo O objetivo do presente estudo foi avaliar os efeitos citotóxicos de cinco cimentos endodônticos (AH Plus, Endomethasone N, EndoSequence BC, MTA Fillapex e Pulp Canal Sealer EWT) utilizando um modelo de cultura celular tridimensional (3D). Utilizou-se um modelo convencional de cultura de células bidimensionais (2D) como técnica de referência para comparação. Os fibroblastos Balb/c 3T3 foram cultivados em culturas de células bidimensionais convencionais e em modelos de cultura de células tridimensionais de colagéno de cauda de rato do tipo I. Em seguida, ambas as culturas de células foram incubadas com eluções dos cimentos endodônticos recém manipulados, durante 24 h. A viabilidade celular foi medida pelo ensaio de MTT. Os dados foram analisados estatisticamente utilizando ANOVA e o teste de Tukey com nível de significância de p<0,05. Todos os cimentos testados exibiram efeitos citotóxicos. Contudo, o efeito citotóxico foi dependente do modelo de cultura e do cimento testado. Os cimentos apresentaram maior citotoxicidade no modelo 2D do que no modelo 3D (p<0,05). Em ambas as condições, a EndoSequence BC apresentou a menor citotoxicidade (p<0,05). MTA Fillapex foi mais citotóxico do que os outros cimentos endodônticos testados (p<0,05), com exceção do AH Plus no modelo de cultura de células 2D (p>0,05). Endomethasone N e EWT mostraram efeitos citotóxicos mais baixos do que AH Plus no modelo de cultura de células 2D (p<0,05); entretanto, não houve diferenças estatísticas entre esses cimentos no modelo de cultura de células 3D. Pode concluir-se que a citotoxicidade foi maior na cultura de células 2D em comparação com a cultura de células 3D. EndoSequence BC selante exibiu a maior citocompatibilidade e MTA Fillapex a menor citocompatibilidade.

Abstract The aim of the present study was to evaluate the cytotoxic effects of five endodontic sealers (AH Plus, Endomethasone N, EndoSequence BC, MTA Fillapex and Pulp Canal Sealer EWT) using a three-dimensional (3D) cell culture model. A conventional bi-dimensional (2D) cell culture model was used as reference technique for comparison. Balb/c 3T3 fibroblasts were cultured in conventional bi-dimensional cell culture and in rat-tail collagen type I three-dimensional cell culture models. Then, both cell cultures were incubated with elutes of freshly mixed endodontic sealers for 24 h. Cell viability was measured by the methyl-thiazol-diphenyltetrazolium assay (MTT). Data were statistically analyzed using ANOVA and the Tukey test at a significance level of p<0.05. All tested sealers exhibited cytotoxic effects; however, cytotoxic effect was culture model- and sealer-dependent. Sealers showed higher cytotoxicity in 2D than in 3D cell culture model (p<0.05). In both conditions, EndoSequence BC showed the lowest cytotoxicity (p<0.05). MTA Fillapex was much more cytotoxic than the other tested endodontic sealers (p<0.05), with the exception of AH Plus in the 2D cell culture model (p>0.05). Endomethasone N and Pulp Canal Sealer EWT showed lower cytotoxic effects than AH Plus in 2D cell culture model (p<0.05); however no statistical differences was observed among these sealers in 3D cell culture model. It may be concluded that cytotoxicity was higher in 2D cell culture compared to 3D cell culture. EndoSequence BC sealer exhibited the highest cytocompatibility and MTA Fillapex the lowest cytocompatibility.

Abstract This study was designed to investigate the resistance to dislodgment provided by MTA HP, a new high-plasticity calcium silicate-based cement. Biodentine and White MTA Angelus were used as reference materials for comparison. Three discs 1 ± 0.1 mm thick were obtained from the middle third of the roots of 5 maxillary canines. Three 0.8-mm-wide holes were drilled on the axial surface of each root disc. Standardized irrigation was performed. Then the holes were dried with paper points and filled with one of the three tested cements. The filled dental slices were immersed in a phosphate-buffered saline (PBS) solution (pH 7.2) for 7 days before the push-out assessment. The Kruskal-Wallis test was applied to assess the effect of each endodontic cement on the push-out bond strength. Mann-Whitney with Bonferroni correction was used to isolate the differences. The alpha-type error was set at 0.05. All specimens had measurable push-out values and no premature failure occurred. There were significant differences among the materials (p <0.05). The Biodentine specimens had the highest push-out bond strength values (p < 0.05). MTA HP had significantly higher bond strength than White MTA (p < 0.05). MTA HP showed better push-out bond strength than its predecessor, White MTA; however, Biodentine had higher dislodgment resistance than both MTA formulations.