Effect of graphene oxide on the mechanical, tribological, and biological properties of sintered 3Y–ZrO2/GO composite ceramics for dental implants

Abstract

Dental implants are in direct contact with living tissue, therefore, biological performance as well as mechanical properties and tribological behavior of implant materials are important and must be systematically investigated. In our study, 3Y–ZrO2 was modified with different concentrations of bioactive, biocompatible graphene oxide (GO). The 3Y–ZrO2/GO composites were fabricated by hot-press sintering. Compared to raw 3Y–ZrO2, addition of GO sharply increased bending strength and fracture toughness, representing an increase of 200% and 41%, respectively. Crack deflection, crack bridging, and GO pull-out were main toughening mechanisms, associated with the formation of a C–O–Zr bond. The addition of GO reduced coefficient of friction and wear rate and lowered surface roughness of 3Y–ZrO2, mainly owing to self-lubricating properties of the composites. In addition, thin film of hydroxyl groups (OH-) on the surface of composites improved wetting properties, as indicated by low contact angle. GO did not cause any obvious signs of cytotoxicity and promoted proliferation, growth, and adhesion of cells. Fully elongated cell morphology was observed on composites. Overall, 3Y–ZrO2/GO composite ceramic with 0.15 wt% GO is promising biomaterial for dental implant applications.