the biological properties of titanium implant depend on its surface oxide film . because the natural oxide film is bioinert, titanium is generally bioactivated by modifying oxide film or coating ca-p layer 自然生成的钛氧化膜是生物惰性的,为赋予钛生物活性,通常对表面氧化膜进行改性或在其表面涂覆羟基磷灰石涂层。