This study was conducted to test the bi-axial flexural load and optical properties of fully stabilized monolithic zirconia (FSZ) after fatigue loading and thermocycling. Partially stabilized monolithic zirconia (PSZ) was tested as a control.

BruxZirRTM Anterior Solid Zirconia ,which is fully stabilized (FSZ) and BruxZirRTM Shaded Zirconia, which is partially stabilized (PSZ) were used in this study.

Bi-axial flexural loads of PSZ was higher than FSZ at both thicknesses. FSZ has higher translucency than the PSZ. The 0.7 mm thickness groups were more translucent, had lower light blockage percentage and bi-axial flexural load than the 1.2 mm thickness groups. A significant number of the FSZ specimens did not survive the fatiguing protocol. All PSZ specimens survived the fatiguing. Fatiguing and thermocycling had no significant effect on the bi-axial flexural loads of the PSZ. None of the changes in the optical properties after fatiguing is clinically significant.