Objective: Indirect composites are promising alternatives as veneering materials for zirconium dioxide (zirconia) ceramic frameworks. This study evaluated the effects of priming agents and a high-flow bonding agent on the short-term bond of an indirect composite material to a zirconia framework material.
Method and materials: Indirect composite (Estenia C and B) was bonded to particle-abraded zirconia samples (Katana, n = 144) using no (control) or 1 of 8 priming agents: All Bond 2 Primer B (ABB), Alloy Primer (ALP), Clearfil Ceramic Primer (CCP), Clearfil Photo Bond (CPB), Clearfil Photo Bond with Clearfil Porcelain Bond Activator (CPB+Activator), Estenia Opaque Primer (EOP), Porcelain Liner M Liquid A (PLA), and V-Primer (VPR) with or without a high-flow bonding agent (Estenia C and B Opaque). Shear bond strength was tested after 24-hour wet storage. Data were analyzed with Levene test for equality of variance, Dunnett T3 multiple comparison, and Mann-Whitney U test (P = .05).
Results: Mean bond strengths without the high-flow bonding agent application varied from 0.1 to 13.6 MPa, whereas bond strengths with bonding agent application ranged from 0.1 to 24.2 MPa. CPB+Activator (containing phosphate MDP and silane) and CPB (containing MDP) revealed the significantly highest bond strength among the 9 groups without high-flow bonding agent application (P < .05). Application of the high-flow bonding agent significantly increased bond strengths (P < .001).
Conclusion: Primers containing either the functional phosphate monomer MDP or an MDP-silane combination provide superior resin bonds of Estenia C and B composite to Katana zirconia. An intermediate high-flow bonding agent further improves the bond between these materials.