Biocompatibility of silicon carbide in colony formation test in vitro. A promising new ceramic THR implant coating material.

We studied the possible use of silicon carbide (SiC) as a ceramic coating material of titanium-based total hip replacement (THR) implants. The idea is to prevent wear debris formation from the soft titanium surface. SiC is a hard and tightly bonding ceramic surface material, and because of these physical properties it is not easily degradable, as is the case with hydroxyapatite. Our previous in vivo and in vitro studies have indicated that SiC and hydroxyapatite are equally biocompatible regarding particle size for phagocytosis. The present cytotoxicity test using JCRB0603 cells showed that 5 microns SiC particles inhibited colony outgrowth by one-third (67% + 10% vs control), while SiC-coated pins did not cause any inhibition and acted similarly to uncoated titanium pins. The results support the hypothesis that SiC is a promising ceramic THR implant coating material.