Abstract
The purpose of the present study was to evaluate ultimate tensile strengths (UTSs) of bonding agents from three 2-step self-etching systems (Clearfil Mega Bond: MB, Fluoro Bond: FB and Unifil Bond: UB) immediately after light-curing. UTSs of the three bonding agents were evaluated at three periods: immediately after irradiation for the bonding agents, immediately after irradiation for a composite resin and 24hours later from irradiation for the bonding agents. Regarding difference in the bonding agents, MB indicated the largest UTS and followed by FB and UB. As for the difference in the three periods, UTS increased from immediately after irradiation for the bonding agents to24hours later from irradiation for the bonding agents. At immediately after the irradiation for the bonding agents, degree of conversion might be low, and further conversion might be progressed by the irradiation for the composite resin and post-irradiation hardening of the bonding agents.
