Adhesive interface and bond strength of endodontic sealers to root canal dentine after immersion in phosphate‐buffered saline

Abstract

This study evaluated the bond strength (BS) and the adhesive interface of four endodontic sealers to root canal dentine, before, and after immersion in phosphate buffered saline (PBS) to simulate an in vivo environment. Eighty roots were instrumented using ProTaper rotatory files, under irrigation with 17% EDTA and 1% NaOCl. Posteriorly were divided into four groups (n = 20) according to the sealer used: Endofill, AH Plus, Sealapex, and MTA Fillapex. Each group was divided into two subgroups (n = 10) and stored at 37°C immersed in water for 7 days and in PBS for 60 days. From each subgroup, 1 mm thick sections were obtained. One section of each region (coronal, middle, and apical) was submitted to the push-out test and failures were observed. Twelve sections of each subgroup (four from each region) were evaluated under SEM. Three-way ANOVA evaluation for BS showed significant differences between groups and regions (P < 0.0001), but not between subgroups (P > 0.05). AH Plus had significantly higher BS than the others sealers, regardless of the analyzed subgroup (Tukey's test, P < 0.5). The most common failures were adhesive to dentine and cohesive of the sealer. The SEM evaluation (Kruskal-Wallis, Mann-Whitney) showed homogeneous adhesive interface formed and sealer tags in all groups with significant statistical differences with AH Plus, regardless of PBS immersion. AH Plus was superior to the other sealers for both BS and quality of interface formation. Immersion in PBS did not interfere on BS or adhesive interface of the sealers tested.

Do smear‐layer removal agents affect the push‐out bond strength of calcium silicate‐based endodontic sealers?

“…This is in accordance with a previous study that showed no differences in MTA Fillapex bond strength in different periods of immersion, even after immersion for 60 days in PBS (Tedesco et al . ). Neelakantan et al .…”

Wear profile of canal wall surfaces and bond strength of endodontic sealers after in situ acid challenge

“…, Tedesco et al . ). Sealapex has calcium hydroxide in its composition and releases calcium ions at acidic pH; however, this sealer is easily dissolved when in contact with moisture (Chang et al .…”

Eficácia dos cimentos obturadores do sistema de canais radiculares frente a desafio ácido <i>in situ</i>

“…A resistência de união ao cisalhamento da interface dentina/cimento/guta-percha foi avaliada pelo teste de push-out por ser amplamente utilizado em Odontologia e permitir a análise nos diferentes terços dos canais radiculares (SAGSEN et al, 2011;CARNEIRO et al, 2012;RACHED-JÚNIOR et al, 2014;TEDESCO et al, 2014;UZUNOGLU et al, 2015;OLIVEIRA et al, 2015). A mesma raiz pode ser utilizada para a confecção de vários corpos de provas, o que reduz o número de dentes humanos necessários para o estudo (DIAS et al, 2014).…”

“…A interação física do cimento com a dentina, geralmente é estabelecida por meio da penetração do material dentro dos túbulos dentinários, proporcionando retenção mecânica RACHED-JÚNIOR et al, 2014;OLIVEIRA et al, 2015). Além disso, a boa aderência dos cimentos às paredes dentinárias é essencial para o selamento da interface material obturador/dentina (TEDESCO et al, 2014;UZUNOGLU et al, 2015. Assim, a degradação do material obturador causada pela queda de pH proveniente dos ácidos do meio bucal pode levar a formação de microfendas na interface adesiva e comprometer o sucesso do tratamento endodôntico AMOROSO-SILVA et al, 2014;HWANG et al, 2015).…”

“…Para calcular a resistência de união (RU), a força adquirida foi transformada em Newtons e convertida em Megapascal (MPa), e dividida pela área lateral do material obturador multiplicada pela aceleração da gravidade (g = 9,81 m/s²)(RACHED-JUNIOR et al, 2014;TEDESCO et al, 2014;OLIVEIRA et al, 2015). O cálculo da área lateral foi realizado com a fórmula da área lateral do tronco do cone (SL): Nesta fórmula, "R" corresponde à medida do raio do material obturador (porção coronal), "r" corresponde à medida do raio do material obturador (porção apical) e "h" à altura/espessura do material obturador.…”