Effect of temporary cements on the microtensile bond strength of self-etching and self-adhesive resin cement

Objective. The aim of this study was to evaluate the microtensile bond strength (µTBS) of self-etching and self-adhesive resin cement systems to dentin affected by the presence of remnants of either eugenol-containing or eugenol-free temporary cements. Materials and methods. Thirty extracted teeth were obtained and a flat dentin surface was exposed on each tooth. Acrylic blocks were fabricated and cemented either with one of two temporary cements, one zinc oxide eugenol (ZOE) and one eugenol free (ZOE-free), or without cement (control). After cementation, specimens were stored in water at 37°C for 1 week. The restorations and remnants of temporary cements were removed and dentin surfaces were cleaned with pumice. Resin composite blocks were cemented to the bonded dentin surfaces with one of two resin cements, either self-etching (Panavia F 2.0) or self-adhesive (RelyX U-100). After 24 h, the specimens were sectioned to obtain beams for submission to µTBS. The fracture mode was evaluated under a stereoscopic loupe and a scanning electron microscope (SEM). Data from µTBS were submitted to two-way repeated-measure ANOVA and the Tukey test (alpha = 0.05). Results. The cross-product interaction was statistically significant (p < 0.0003). The presence of temporary cements reduced the bond strength to Panavia self-etching resin cements only (p < 0.05). Fracture occurred predominantly at the dentin–adhesive interface. Conclusions. The presence of eugenol-containing temporary cements did not interfere in the bond strength to dentin of self-adhesive resin cements.