Cytocompatibility of two coating materials, amorphous alumina and silicon carbide, using human differentiated cell cultures.

The cytocompatibility of two coating materials, amorphous alumina and silicon carbide deposited by radio-frequency sputtering, was studied using alveolar bone osteoblasts and gingival fibroblasts from human healthy tissues. Cytocompatibility was assessed at the level of both the basic (attachment, proliferation and cell protein content) and the specific features (intracellular alkaline phosphatase activity and the cytoskeleton) of the cells in direct contact with the coating. Titanium was used as the reference material. The results showed that both silicon carbide and amorphous alumina are cytocompatible for human fibroblasts and osteoblasts, whereas titanium appears the least cytocompatible of all the three substrates. Moreover, the amorphous alumina coating seems slightly bioactive. It seems that these coatings, particularly amorphous alumina, could be used to protect alloys against corrosion, and consequently combine the good mechanical properties of the alloys with the good biocompatibility of the coatings. These coatings seem to perform more suitably than titanium if the strength of the bond between the coating and the underlying alloys is strong enough to give a stable composite material.