Abstract: Solubility, pH, ion release, cytotoxicity, and osteoclastogenesis inhibition in bone marrow-derived monocyte macrophages (BMMs) were evaluated in EndoSequence BC Sealer (END), Bio-C Sealer (BC), and Sealer Plus BC (SPBC). pH was determined after immersion of the sealers in deionized water (DW) and Minimum Essential Medium Alpha (α-MEM). Solubility was obtained by mass loss. Ion release was measured by using X-ray fluorescence spectroscopy (XRF). Cytotoxicity was evaluated by MTT assay. Inhibition of osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP). Data were analyzed using the t-test, ANOVA and Tukey/Dunnett's post-hoc tests (α = 0.05). END had the highest pH in DW (p < 0.05), and BC, in α-MEM (p < 0.05). Solubility in DW was the lowest for SPBC (p < 0.005). The highest calcium release was observed for BC in DW at 12 h (p < 0.05), and in α-MEM at 12 and 24 h (p < 0.05). The lowest toxicity was detected for END (p < 0.05). BC had the highest inhibitory effect on osteoclasts (p < 0.05). Overall, the highest solubility and pH values were found in DW. However, the calcium silicate-based sealer showed higher solubility than the ISO standards. Calcium release was the highest for BC. END showed the highest cell viability, and BC, the highest osteoclast inhibition.

Abstract: The aim of this study was to investigate the effects of different post space irrigation protocols for removing residual filling material from dentin walls, by using microcomputed tomography (micro-CT), and the influence of these protocols on dentin microhardness. Bovine incisors (n = 35) were filled with the single-cone technique and MTA Fillapex (Angelus, Londrina, PR, Brazil). Post space preparation (PSP) was performed 7 days after filling, using the Odous Touch electrical system (Odous De Deus Ind. e Com., Belo Horizonte, MG, Brazil), followed by post space irrigation using manual irrigation, passive ultrasonic irrigation, or Easy Clean, together with 2.5% sodium hypochlorite (NaOCl), or with 2.5% NaOCl and 17% EDTA (NaOCl/EDTA). Micro-CT scans were performed at three time points. The residual filling material was evaluated at three levels: cervical, middle and apical. The Knoop test was measured with four indentations around the canal lumen at three dentin depths: X (100 μm), Y (200 μm) and Z (400 μm). Statistical analysis was performed using ANOVA (p < 0.05). The effects of the activation method (p < 0.001), and the root level (p = 0.013), as well as the interaction between the irrigant and the activation method (p = 0.041), led to different percentages of residual filling material. Lower amounts of residual filling material were observed at the cervical versus the middle and apical levels (p < 0.05). No significant differences were observed in dentin microhardness (p > 0.05). The best removal of the residual filling material was performed using the Easy Clean tip and NaOCl/EDTA, regardless of the activation methods.

Resumo O objetivo deste estudo foi avaliar a presença de resíduos após o alívio do canal (AC) e verificar se o deslocamento apical da guta-percha foi afetado pelos momentos e métodos de AC em dentes obturados pela técnica do cone único. Os canais radiculares de 20 dentes incisivos bovinos foram instrumentados com Reciproc e obturados com cone único e AH Plus. As amostras foram divididas em 4 grupos de acordo com o momento e método de AC (n=5): broca imediato, termocompactador imediato, broca tardio e termocompactador tardio. Escaneamentos em micro-CT foram realizados antes e após o AC para análise dos resíduos da obturação (1) e do deslocamento apical (2). Os dados foram analisados empregando ANOVA em 2 fatores com medida repetida (1), ANOVA em dois fatores (2), seguidas do teste de Tukey (α=0,05). A porcentagem de resíduos remanescentes foi influenciada pelos métodos (p=0,044), momentos (p=0,006), pelo fator de repetição terços do canal (p<0,001), e pelas interações entre métodos e terços (p<0,001), e momentos e terços (p=0,044). Já para o deslocamento apical da obturação do canal radicular foi detectada influência significativa para os métodos (p=0,008), no entanto, nenhuma diferença foi encontrada entre os momentos (p=0,617). Em geral, AC usando brocas resultou em preparo mais homogêneo dos canais radiculares, principalmente quando realizado imediatamente após a obturação. Para todas as outras combinações entre métodos e momentos de AC, o terço médio e apical apresentaram significativamente maiores resíduos remanescentes. O método termo realizado nos dois momentos e o método broca de preparo realizado imediatamente resultaram em deslocamento na direção apical, representando a extrusão do material de obturação no canal radicular.

Abstract The purpose of this study was to evaluate the presence of residues after post space preparation (PSP) and establish whether the apical displacement of the gutta-percha was affected by the moments and methods of PSP in teeth filled by the single-cone technique. The root canals of 20 bovine incisor teeth were instrumented with Reciproc and filled with single-cone and AH Plus. The specimens were divided into 4 groups according to the moment and method of PSP (n=5): immediate with drill, immediate with thermoplasticizer, delayed with drill and delayed with thermoplasticizer. Micro-CT scans were performed before and after the PSP for residues of the root canal filling (1) and analysis of apical displacement (2). Data were analyzed by using 2-way repeated measurement ANOVA (1) and 2-way ANOVA (2) followed by the Tukey’s test (a=0.05). Significance effect on the residues percentage remaining for methods (p=0.044), for moments (p=0.006), for thirds repetition (p<0.001), and for interaction between methods and thirds (p<0.001), and moments and thirds (p=0.044). Significance effect on the apical displacement of root canal filing was detected for methods (p=0.008), however no difference was found between moments (p=0.617). In general, PSP using drill resulted in more homogeneous root canal preparation, mainly when made immediately. For all other combinations between methods and moments for PSP, the middle and apical thirds presented significant higher residues remaining. Thermo method performed in both moments and the drill method performed immediately had displacement in the apical direction, representing extrusion of the root filling material.

Este estudo avaliou a influência do tipo de silano e a aplicação de temperatura no silano na resistência de união por push-out entre pinos de fibra de vidro com núcleo de preenchimento em resina composta e cimento resinoso. Cento e sessenta pinos de fibra de vidro (Exacto, Angelus, Londrina, PR, Brasil) receberam tratamento de superfície com peróxido de hidrogênio a 24%. Os pinos foram divididos em 8 grupos com dois fatores em estudo: temperatura de secagem de ar após a aplicação do silano (temperatura ambiente e 60 ºC) e o tipo de silano: três pré-hidrolisados - Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE) e um silano de dois frascos - Silane Coupling Agent (Dentsply). Para o teste de resistência de união entre pino e núcleo de preenchimento, os pinos (n=10) foram centralizados em uma matriz plástica cilíndrica e a resina composta (Filtek Z250 XT, 3M ESPE) foi incrementalmente inserida e fotopolimerizada. Para o teste de resistência de união entre pino e cimento resinoso (RelyX U100, 3M ESPE) 80 raízes de incisivos bovinos (n=10) foram preparadas e receberam os pinos de fibra de vidro. Teste de push-out foi usado para mensurar a resistência de união. Os dados foram analisados por ANOVA fatorial seguido do teste de Tukey (a=0,05). Temperatura e silano não tiveram influência na resistência de união entre núcleo de preenchimento e pino. Entretanto, para a resistência de união entre pino e cimento resinoso, o aumento da temperatura resultou em um melhor desempenho para Silane Coupling Agent, Silano e RelyX Ceramic Primer. Além disso, na temperatura ambiente Silane Coupling Agent teve a menor resistência de união. O efeito da secagem de ar quente é dependente da composição do silano. Concluindo, o uso do silano é influenciado pela molhabilidade dos materiais resinosos e os silanos pré-hidrolisados são mais estáveis comparados ao silano de dois frascos.

This study evaluated the influence of silane type and temperature of silane application on push-out bond strength between fiberglass posts with composite resin core and resin cement. One hundred and sixty fiberglass posts (Exacto, Angelus) had the surface treated with hydrogen peroxide 24%. Posts were divided in 8 groups according to two study factors: air-drying temperature after silane application (room temperature and 60 ºC) and silane type: three pre-hydrolyzed - Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE) and one two-component silane - Silane Coupling Agent (Dentsply). The posts (n=10) for testing the bond strength between post and composite core were centered on a cylindrical plastic matrix and composite resin (Filtek Z250 XT, 3M ESPE) that was incrementally inserted and photoactivated. Eighty bovine incisor roots (n=10) were prepared for testing the bond strength between post and resin cement (RelyX U100, 3M ESPE) and received the fiberglass posts. Push-out test was used to measure the bond strength. Data were analyzed by two-way ANOVA followed by Tukey's test (a=0.05). ANOVA revealed that temperature and silane had no influence on bond strength between composite core and post. However, for bond strength between post and resin cement, the temperature increase resulted in a better performance for Silane Coupling Agent, Silano and RelyX Ceramic Primer. At room temperature Silane Coupling Agent showed the lowest bond strength. Effect of the warm air-drying is dependent on the silane composition. In conclusion, the use of silane is influenced by wettability of resinous materials and pre-hydrolyzed silanes are more stable compared with the two-bottle silane.