RESUMO
This in vitro study evaluated the effect of the application and previous photoactivation of bonding adhesives in lithium disilicate ceramics. This was achieved by analyzing the bond strength of the cement-ceramic interface, nanohardness and elastic modulus of bonding adhesives and resin cements. The bonding adhesives used were Scotchbond Multi-Purpose (SBMP); Scotchbond Multi-Purpose light-cured (SBMP+LC); Single Bond 2 (SB2); Single Bond 2 light-cured (SB2+LC); Single Bond Universal (SBU) and Single Bond Universal light-cured (SBU+LC). After luting the ceramic in composite resin blocks, all specimens were subjected to 10,000 thermocycles. Sticks were obtained for the microtensile bonding strength test and the nanohardness and elastic modulus of the bonding adhesive and resin cements. Data were submitted to one-way ANOVA and Fishers tests (α =0.05). The results indicated that the bonding strength and mechanical properties were influenced by the interaction of the bonding adhesive and resin cement. For the mechanical properties analyzed, no statistically significant differences were observed between the groups. Single Bond Universal was the only system that was effective with or without previous light activation. For the other adhesive systems, Scotchbond Multi- Purpose and Single Bond 2, the previous light activation was necessary to optimize the bonding strength of the adhesive interface.
