Clinical chipping of zirconia all-ceramic restorations

Abstract

Advancements in CAD/CAM systems employed in dentistry have made possible the application of yttria tetragonal zirconia polycrystal (Y-TZP) in zirconia-based all-ceramic restorations. Y-TZP has excellent flexural strength and fracture toughness and is used in molar crowns as well as frameworks of fixed partial dentures (FPDs). The use of Y-TZP in clinics has increased over the past several years, and it is now used in implant abutments and denture frameworks. While the demand for Y-TZP is increasing, chipping of porcelain used in the zirconia framework has been noted as a problem in zirconia-based all-ceramic restorations from a clinical point of view. We have previously used Cercon® smart ceramics with Y-TZP frames in clinics but have noticed the chipping of porcelain in a large number of cases over time. This review article focuses on the chipping of zirconia all-ceramic restorations by taking into account the following aspects: (1) clinical performance of zirconia all-ceramic restorations, (2) influence of frame thickness and porcelain firing schedules, and (3) reduction in porcelain chipping.