Effect of polymerization mode of adhesive and cement on shear bond strength to dentin

To investigate the shear bond strength to dentin when two resin adhesive systems in light-cure, dual-cure, and auto-cure modes were used with three resin cements. This was done to determine the degree of compatibility that exists when resin products with different polymerization mechanisms are used together.

Three hundred non-carious human molars were divided into 30 test groups in which Prime & Bond NT and ScotchBond Multi-Purpose were used as adhesives with Calibra, Nexxus and Variolink cements to attach Rexillium III posts to flattened dentin surfaces. Debonding was achieved with an Instron testing machine and mean shear bond strengths were determined for each test group. The data were subjected to three-way ANOVA and post-hoc LSD testing to determine whether significant differences existed between the test groups.

Bond strengths achieved were affected by the adhesive, the cement, and the cement curing mode. In general, the auto-cure application of the three cements demonstrated reduced shear bond strengths, both with respect to the different adhesives and their curing modes as well as compared to the dual-cure technique of the same cement. Additionally, Prime & Bond NT demonstrated considerably more variability than ScotchBond Multi-Purpose when used with both dual-cure and auto-cure varieties of the three cements. The bond strengths of resin cements depend on the curing mode of the cement and the adhesive. Unlike with direct light-cured resin composites, combining adhesive systems and dual-cured resin cements from different manufacturers may be contraindicated.