Bond Strength of Bis-GMA/TEGDMA Resin Cements to Zirconia

Objectives: This study investigated the bond strengths of three Bis-GMA/TEGDMA resin cements to zirconia.

Methods: Three resin cements including Clearfil Esthetic Cement (EC), Panavia F2.0 (PV), and Clearfil SA Luting (SA), and two silane coupling agents including Clearfil Ceramic Primer (CP) and Clearfil Porcelaine Bond Activator (PB) were used in this study. All products are manufactured by Kuaray Medical. All materials except EC contain adhesive monomer, MDP. Pairs of disk specimens (10 mm diameter, 3 mm thick, and 8 mm diameter, 3 mm thick) were prepared using a dental zirconia system (Cercon, Dentsply Ceramco). Bonding surfaces of disks were polished with a 600-grid silicon carbide paper and air abraded with 50 µm alumina particles. The abraded surfaces were treated with respective silane coupling agents for silanated specimen groups (CP/EC and PB/PV). Bonding areas were regulated using an adhesive tape with a 5 mm diameter opening. Shear bond specimens were fabricated by bonding a pair of disks using one of five bonding systems mentioned above. All the specimens (five specimens for each group) were stored in 37°C distilled water for 24 hours. Shear bond strengths were determined before and after thermo-cycling (4°C - 60°C, 1-minute dwell time for 50,000 cycles) at a 1.0 mm/min crosshead speed. The data were statistically analyzed by three-way ANOVA and Tukey's test (a=0.05).

Results: The results of shear bond strengths are presented in the table below. Most of the specimens exhibited adhesive failures at the zirconia/cement interface. Identical small and capital letters denote no significant difference within the same thermo-cycling groups and the same material groups, respectively (p>0.05).

Conclusion: The bond strengths of Bis-GMA/TEGDA resin cement were influenced by an addition of adhesive monomer, MDP to cements or silane coupling agents.

Table. The values of Shear Bond Strengths (mean ± s.d.), Unit: MPa