Shear bond strength between veneering ceramics and ceria-stabilized zirconia/alumina.

STATEMENT OF PROBLEM Ceria-stabilized tetragonal ZrO(2)/Al(2)O(3) nanocomposite (Ce-TZP/A) offers superior properties compared to yttria-stabilized zirconia (Y-TZP). However, the bond quality to veneering ceramics has not been investigated. PURPOSE The purpose of this study was to evaluate the bond strength of different veneering ceramics to Ce-TZP/A. MATERIAL AND METHODS Cubes of Ce-TZP/A (NANOZR) (edge length, 10 mm) were layered with veneering ceramics (5 mm in thickness) with or without application of a liner and sheared at the interface. The effect of different surface treatments (polished with 3-mum diamond paste or airborne-particle abraded) was evaluated with 1 veneering ceramic (Cerabien ZR). Shear bond strength of 5 additional veneering ceramics (IPS e.max, Initial ZR, Triceram, Vintage ZR, or VITA VM 9) to polished Ce-TZP/A was measured (n=10). Polished Y-TZP (Hint-ELs ZrO(2) HIP) veneered with 2 ceramics (Cerabien ZR, Vintage ZR) served as the control. Mean shear bond strength values (MPa) were calculated. The means were statistically analyzed with 2-way ANOVA for the effect of surface treatment and liner, 2-way ANOVA for the effect of different veneering ceramic brands and liner, and 3-way ANOVA for the effect of substrate, veneering ceramic brands, and liner, as well as 1-way ANOVA for the differences between the veneering ceramics. A post hoc Scheffé test was used (alpha=.05). RESULTS The effects of surface treatment (P=.007) or application of liner (P<.001) were significant. Shear bond strength with different veneering ceramics showed bond strength values with means ranging between 14.2 +/-1.7 MPa (IPS e.max with liner) and 27.5 +/-4.2 MPa (VITA VM 9). A significant difference was found between the results of shear bond tests with Y-TZP and Ce-TZP/A (P=.022). The application of a liner on Y-TZP had no significant effect. CONCLUSIONS Airborne-particle abrasion is not necessary to enhance the shear bond strength of the evaluated veneering ceramics to Ce-TZP/A. Liners impair the shear bond strength of veneering ceramics to Ce-TZP/A.