BIOCOMPATIBILITY OF WEAR-RESISTANT COATINGS IN ORTHOPEDIC-SURGERY IN-VITRO TESTING WITH HUMAN FIBROBLAST CELL-CULTURES

The in vitro biocompatibility of six wear-resistant coatings that were devised as an alternative to polyethylene in resurfacing hip arthropl asties was assessed. The coatings were applied on glass-cover slips vi a the chemical vapour deposition (CVD) and physical vapour deposition (PVD) methods. Testing was performed in human fibroblast cultures and toxicity was evaluated by use of total cell surface quantitation, ligh t and scanning electron microscopy. Multiple cracks were observed in t he tungstenhydrogencarbide (WCH) and chromiumcarbide (CrC) coatings im mediately after adding the growth medium. These surface alterations we re not related to the presence of fibroblasts. Because of these surfac e changes, the general biocompatibility of WCH and CrC could not be as sessed. Chromiumoxide (Cr2O3) caused severe alterations in cellular mo rphology followed by significant cytotoxicity. Alumina (Al2O3), titani umnitride (TiN) and titaniumcarbide (TiC) coatings caused no adverse e ffects on cells in culture. The fibroblasts showed a rapid and logarit hmically stable growth curve on these three materials. They merit furt her investigation as a wear-resistant coating for orthopaedic implants .