Debonding/crack initiation and flexural strengths of bilayered zirconia core anveneering ceramic composites

The aim of this study was to evaluate the effects of the kinds of veneering ceramics and veneering methods on the debonding/crack initiation and 3-point flexural strengths in bilayered zirconia core and veneering ceramic composites. Zirconia block was used as core material, and Cerabien ZR and Lava Ceram for the layering technique and IPS e.max ZirPress and Amber LiSi-POZ for the heat pressing technique were used as veneering materials. Both debonding/crack initiation and 3-point flexural strengths of bilayered zirconia core and veneering ceramic composites as well as the bi-axial flexural strengths of veneering materials, were higher when using heat pressing technique than layering technique. It was identified that not only bonding strength between zirconia core and veneering materials but also the intrinsic strength of veneering ceramic should be high to prevent chipping of veneering material.