Analysis of the interface and bond strength of resin‐based endodontic cements to root dentin

Abstract

This study evaluated by scanning electron microscopy the interface between root dentin and resin cements, with or without additional application of a dual-cured one-step self-etching dentin adhesive. In addition, the push-out bond strength of these materials to dentin was evaluated. Root canals of 50 maxillary human canines were subjected to biomechanical preparation and randomly assigned into five groups (n = 10) according to the obturation employed: I. AH Plus/gutta-percha; II. Endo-REZ/gutta-percha; III. Epiphany SE/Resilon; IV. Endo-REZ/gutta-percha + adhesive; and V. Epiphany SE/Resilon + adhesive. After obturation, two cross sections of 1.0 mm of each third of the root were obtained and analyzed by SEM and push-out. Data were analyzed by Kruskal-Wallis, Two-way ANOVA and Tukey's HSD tests (α = 5%). Significant differences occurred between scores for gap parameters and tags; greater tag formation resulted for Epiphany SE (P < 0.05). There were also significant differences between groups for the bond strength. AH Plus (1.24 ± 0.70) showed higher values (P < 0.05) compared to groups II (0,17 ± 0.19), III (0.10 ± 0.06), IV (0.09 ± 0.08), and V (0.06 ± 0.03), which were statistically similar (P > 0.05). There was no significant difference between the root thirds (P > 0.05). It was concluded that the use of a self-etching adhesive system did not improve the adhesion of resin-based sealers to dentin and that AH Plus showed better bond strength when compared to other cements.