Zirconate coupling agent for bonding resin luting cement to pure zirconium

PURPOSE: To evaluate the shear bond strengths of two dual-cured resin luting cements to pure zirconium and the effect of zirconate coupling agent on the bond strength. METHODS: The two different-shaped pure zirconium specimens (99.9%) were untreated or treated with one of the four primers including zirconate coupler and then cemented together with one of the two dual-cured resin luting cements. Half of the specimens were stored in water at 37 degrees C for 24 hours and the other half thermocycled 20,000 times before shear bond strength testing. RESULTS: Regardless of the resin luting cement and thermocycling, specimens treated with the mixture of zirconate coupler and resin bonding agent showed the highest shear bond strength among the five treatments. Surface treatment with the mixture of zirconate coupler and resin bonding agent showed significantly greater shear bond strength compared with other treatments at 20,000 thermocycles. The application by the mixture of zirconate coupler and resin bonding agent on the pure zirconium metal surface appears to be effective for bonding between zirconium and dual-cured resin luting cements.