Effect of Y2O3 content on the mechanical and optical properties of zirconia-based dental ceramics

Abstract The present work aims to identify variations in the mechanical and optical properties of samples produced from ZrO2 powders containing different Y2O3 contents (3Y-TZP, 4Y-PSZ, and 5Y-PSZ) intended for applications such as dental prostheses. Disc-shaped samples (n=60) were uniaxially pressed, sintered at 1550 °C-2 h, and characterized. Dense ceramics were obtained for all compositions. The increase of Y2O3 content led to the increase of the cubic-ZrO2 phase with a reducing tetragonal phase. As a result, mechanical properties were reduced (flexural strength of 1375~590 MPa and fracture toughness 7.2~4.1 MPa.m1/2) while translucency was improved. Based on the requirements of ISO-6872 standard, 3Y-TZP presents versatility for non-aesthetic applications, while 5Y-PSZ is recommended for aesthetic applications such as anterior teeth due to better translucency.