Tensile bond strength of two dentin adhesive systems.

The tensile bond strength of one third-generation (XR Bond) and one fourth-generation (Optibond) adhesive system to dentin was compared. The influence of acid etching of dentin on the bond strength in the XR Bond system was also evaluated. In addition, two kinds of curing (photo and dual) of the Optibond system were evaluated. The Optibond system showed a statistically significant higher tensile bond strength to dentin than the XR Bond system. Etching of the dentin before application to XR Bond did not significantly improve the bond strength to dentin. Both photo and dual curing showed similar bond strengths two hours and seven days after sample preparation.