Reconstruction and regeneration of surface oxide film on metallic materials in biological environments

Phenomena concerning surface oxide films of conventional metallic biomaterials in biological environments are discussed. Compositions of the surface oxide films on metallic biomaterials such as titanium, titanium alloys, austenitic stainless steel, and cobalt-chromium alloy, are reviewed on the basis of empirical data. The composition of the surface oxide film changes even though the film is macroscopically stable according to reactions between the surface of metallic materials and living tissues. Therefore, reconstruction of the surface oxide film in biological environments is also reviewed. In addition, the repassivation time and regeneration of the surface oxide films of metallic materials are discussed. Dissolution of surface oxide film with active oxygen species that are one of the causes of dissolution of metallic materials is also explained.