Keynote Address; Fracture (chipping) of the Veneering Layer in Porclain/Y-TZP Prostheses: Understanding the Causes and Proposing Solutions

Abstract Body: Clinical studies to date reported high survival rates with fixed dental prosthesis (FDPs) made of yttria partially stabilized zirconia (Y-TZP). Yet, the veneering ceramic layer that is responsible for the final optical outcome and anatomy of the FDP, with lower mechanical properties than Y-TZP, continues to exhibit high chipping rate. This clinically undesirable situation, which is in fact the failure of the system, may interfere with appearance, function and be costly in cases of early failures. Since understanding the factors related to veneer ceramic chipping may diminish such clinical failures, this keynote will present information on the mechanical and microstructural characteristics of veneering ceramics, challenges posed onto this material in the oral environment, mechanisms of generation of thermal residual stress profiles during cooling in bilayered FDPs and process related issues to circumvent chipping.