Physicochemical and biological properties of Y-TZP ceramics modified by infiltration with different bioactive glasses for dental implant

Abstract

Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) are widely used as dental materials due to their excellent mechanical properties and appearance. However, its biological inertness limits its application for dental implants. In this study, the dry-press molded and low-temperature pre-sintered Y-TZP compacts were immersed in 58S, 68S, and 77S bioactive glass (BG) sols prepared by sol-gel method. The different BG sols were infiltrated into the Y-TZP pre-sintered compacts under negative pressure. After aging and drying, the infiltrated Y-TZP compacts were rapidly sintered at 1410 °C through microwave sintering. Results of physicochemical characterizations, including phase composition, morphology, microstructure, and flexural strength, confirm that these three BGs have successfully infiltrated into the Y-TZP matrix and remained therein. Although the modification compromised the densification and mechanical properties of Y-TZP, the flexural strength of the modified Y-TZP/BG samples could still meet the requirement of ISO 6872:2015 (Class 4: >500 MPa). Furthermore, the modified Y-TZP/BG samples showed better bioactivity, primarily characterized by superior protein adsorption capacity and the sustained release of osteogenic-related ions into the culture medium without inducing significant pH changes. Cells cultured on the surface of Y-TZP samples also exhibited better adhesion, spreading, viability, proliferation, and osteogenic differentiation. The enhanced bioactivity and osteogenic inductivity of Y-TZP/BG samples highlight the promising potential of Y-TZP ceramics infiltrated with different BGs for dental implant applications.