Shear Bond Strengths of a Single-Step Bonding System to Enamel and Dentin

An experimental primer was developed as a single-step bonding system for resin-modified glass ionomer cements (GIC). Efficacy of this primer on adhesion of resin-modified GICs and resin composite to enamel and dentin was evaluated by shear bond test and SEM observation. Good bond strengths to enamel were obtained (> 11 MPa), whereas significantly low bond strengths to dentin were obtained using a single coat of the primer. However, double-coating improved the bond strengths to dentin (> 8 MPa). SEM observations indicated that the primer functioned as a mild conditioner to remove the smear layer on enamel or dentin surfaces. A hybrid layer was observed at the cross-sectional view of the GIC/dentin interface. These findings suggested that good adhesion to enamel and dentin could be achieved using a single-step bonding system.