Influence of light activation of simplified adhesives on the shear bond strength of resin cements to a leucite-reinforced ceramic

OBJECTIVE: This study aims to evaluate the influence of the light activation of simplified adhesives on the shear bond strength of resin cements to a glass-ceramic. Three factors were evaluated: (1) cement in two levels (light cured and dual cured); (2) adhesive in two levels (Single Bond 2 and Single Bond Universal), and (3) light activation in two levels (yes or no). MATERIALS AND METHODS: Thirty-two 1-mm thick slices of a leucite-reinforced glass-ceramic (IPS Empress CAD) were divided into eight groups according to adhesive (Single Bond 2 or Single Bond Universal), cement (AllCem Veneer or AllCem), and light activation of the adhesive before application of the cement (yes or no). Ceramic surfaces were etched for 60 s with 5% hydrofluoric acid, and adhesives were applied. Four cement cylinders were made over each ceramic slice (n = 16) and then submitted to shear bond strength tests. STATISTICAL ANALYSIS: Data were analyzed with three-way ANOVA and Tukey (α = 0.05). RESULTS: There were significant differences between adhesives (P < 0.0001) and no differences between cements (P = 0.0763) and light activation (P = 0.4385). No interaction effect occurred (P = 0.05). Single Bond 2 showed higher bond strength than Single Bond Universal. CONCLUSIONS: The light activation of the adhesive before the application of the resin cement did not influence the bond strength.