Abstract: Bone repair materials are disclosed, from which ions are hardly eluted in living body and which are superior in apatite-forming ability and resistance to apatite peeling and have a scratch resistance high enough for practical use. The material comprises a substrate made of titanium or titanium alloys, and a surface layer, made substantially of titanium oxide, along the surface of the substrate. The substrate has on the surface thereof irregularities of from 1 nm to 10 ?m in average in both width and depth. The layer has a zeta potential of +4.5 mV or more under an aqueous solution environment of pH 6 to 8, and a critical scratch resistance of 35 mN or more when vibration 100 ?m in amplitude is added to a stylus with a spring constant of 200 g/mm on the surface layer and the stylus is moved at a rate of 10 mm/sec under a load increasing at a rate of 100 mN/min.

Abstract: Bone repair materials are disclosed, from which ions are hardly eluted in living body and which are superior in apatite-forming ability and resistance to apatite peeling and have a scratch resistance high enough for practical use. The material comprises a substrate made of titanium or titanium alloys, and a surface layer, made substantially of titanium oxide, along the surface of the substrate. The substrate has on the surface thereof irregularities of from 1 nm to 10 ?m in average in both width and depth. The layer has a zeta potential of +4.5 mV or more under an aqueous solution environment of pH 6 to 8, and a critical scratch resistance of 35 mN or more when vibration 100 ?m in amplitude is added to a stylus with a spring constant of 200 g/mm on the surface layer and the stylus is moved at a rate of 10 mm/sec under a load increasing at a rate of 100 mN/min.