Effect of sandblasting and various metal primers on the shear bond strength of resin cement to Y-TZP ceramic.

Objectives: This study was designed to evaluate the effect of sandblasting and metal primers on the shear bond strength of three commercial resin cements to Yttria-Tetragonl Zirconia Polycrystal (Y-TZP) ceramics.

Methods: One hundred and twenty Y-TZP ceramic cylinders (Ø7 mm x 12 mm) were embedded in polytetrafluoroethylene (PTFE) molds using PMMA. The specimens were divided randomly into 12 groups (n=10), according to the surface treatments (control; sandblast-only; metal primer-only; sandblast+metal primer) and metal primer-resin cements (Alloy primer - Panavia F 2.0, V-primer - Superbond C&B, Metaltite - M bond) rendered. The mixed resin cements were placed onto the treated zirconia surfaces in cylindrical shape (Ø3 mm x 3 mm) using PTFE molds. All specimens were thermocycled (5 and 55 degrees C, 5000 cycles) and subjected to shear bond strength test by a universal testing machine with a crosshead speed of 0.5 mm/min. All data were statistically analyzed using two-way ANOVA and multiple comparison Scheffé test (alpha=0.05), and SEM images of the fractured areas were used to evaluate the fracture mode.

Results: In Panavia F 2.0, the bond strength of the specimens treated with sandblasting and metal primer (Alloy primer) was significantly higher than those of the other subgroups. In Superbond C&B and M bond, sandblasting significantly increased the shear bond strength, but the effect of metal primers (V-primer and Metaltite) was not significant and there was disordinal interaction.

Significance: Metal primers are not always effective for bonding between Y-TZP ceramics and resin cements. Even though a metal primer is not enough to be used alone, combined application with sandblasting seems to be an appropriate pretreatment for improving the bond strength of resin cement to Y-TZP ceramics, especially in Panavia F 2.0.