In vitro shear bond strength of two resin composites to dentin with five different dentin adhesives

Objective: The aim of this in vitro study was to evaluate the shear bond strength to dentin of five different dentin bonding agents in combination with two resin composites (Tetric and Z-100). Method and materials: Human third molars were selected for the study, and cylindrical posts of either Tetric or Z-100 were bonded vertically to a standard flat dentinal area, prepared on the buccal surface of the teeth. A chisel-shaped shearing blade, attached to the crosshead of a universal testing machine, was positioned so that its edge was immediately adjacent to the adhesive joing. The shear bond strengths to dentin of 10 resin composite-dentin adhesive combinations were measured. Results: The results showed that the bond strength of dentin bonding agents may depend on the choice of restorative material. The in vitro bond strength of dentin bonding agents also differed significantly. In several cases, the bond strength exceeded the cohesive strength of dentin. Conclusion: It seems important for clinicians to be acquainted with the variation in bond strength values that is experienced with any bonding system.