In vitro tribological and biocompatibility evaluation of sintered silicon nitride

In the present work, dense silicon nitride (Si3N4) was developed using pressureless sintering for biomedical applications. The Si3N4 samples with 15 wt% sintering additives (Al2O3 + Y2O3) were sintered at 1700 °C for 2 h followed by characterization in terms of phase constituents, mechanical, in vitro tribological and biological properties. In vitro tribological tests in simulated body fluid (SBF) revealed that the wear rate and coefficient of friction of Si3N4 reduced by one order of magnitude in the presence of 10% fetal bovine serum (FBS). The in vitro biocompatibility evaluations using human osteoblast-like cells (MG63) confirmed that the sintered Si3N4 samples were non-cytotoxic.