VARIATION OF OXIDE-FILMS ON TITANIUM INDUCED BY OSTEOBLAST-LIKE CELL-CULTURE AND THE INFLUENCE OF AN H2O2 PRETREATMENT

Variations of titanium oxide films induced by osteoblast-like cells in a rat calvaria culture system and the influence of an H2O2 pretreatme nt have been investigated by using X-ray photoelectron spectroscopy an d electrochemical impedance spectroscopy. For abraded titanium, the re sults revealed that phosphate and calcium ions may incorporate into th e surface oxide film during the cell culture, forming a precipitate wi th a Ca/P ratio near that of hydroxyapatite. Oxidized carbon also was found in the surface layer, most Likely precipitated hydroxylcarbonate d apatite (HCA). The H2O2 pretreatment of titanium in a phosphate-buff ered saline solution results in a 10-fold thickened porous oxide film and large amounts of surface hydroxyl groups as well as a certain amou nt of phosphate ions inside the oxide film. During the cell culture, t he H2O2-treated titanium surface favors the ion incorporation and prec ipitation of the HCA-like compound, which probably is inlaid into the oxide film. Osteoblast-like cells on the H2O2-treated titanium showed a more active morphology during the initial stage compared with cells on abraded titanium. Moreover, bone-like nodule formation and minerali zation appear to be related to the precipitation of the HCA-like compo und on the surface. The results are discussed with respect to corrosio n resistance, ion incorporation and precipitation of the HCA-like comp ound on the surface, osseointegration, and bioactivity of titanium imp lants, (C) 1998 John Wiley & Sons, Inc.