Fractographic study of the interface between zirconia Y-TZP and its veneering ceramic after shear strength testing

Abstract

This study analyzed the shear strength and fracture characteristics of the interface between zirconia samples and their veneering ceramic compared with a metal- ceramic and a lithium disilicate glass-ceramic control group together with an assessment of the possible relationship between the fracture characteristics and the recorded shear strength. The greatest shear strengths corresponded to the lithium disilicate glass-ceramic control group followed by the metal-ceramic control group, with lesser strengths in the zirconia groups. Since the fractographic study showed cohesive-type failure to predominate in the zirconia samples, it is concluded that improvements are needed in the veneering ceramic and liner used in zirconia restorations.