Effect of pretreatment reagent for enamel on the adhesion of resin composite.

Aqueous solutions of methacryloyl tyrosine amide (MTYA), glyceryl methacrylate (GM), glutaraldehyde and succinic acid were prepared and their effectiveness as pretreatment reagents was evaluated by measuring the tensile bond strengths between resin composite and polished enamel. Pretreatment of polished enamel with MTYA.GM.S3 (A: 6% MTYA + 70% GM aqueous solution, B: 3% succinic acid aqueous solution) gave bond strengths of about 7 MPa, whereas pretreatment with MTYA.G.GM.S3 (A: 6% MTYA + 70% GM aqueous solution, B: 3% succinic acid + 2% glutaraldehyde aqueous solution) gave values of about 5 MPa. The mean bond strengths of each after 60 s of scrubbing with MTYA.GM.S3 or by MTYA.G.GM.S3 were raised to about 9.5 MPa, and the type of bond failure was fracture of the bonding agent. Although there were no resin tags, it was found that resin composite was able to adhere to polished enamel without acid etching.