Development of titanium alloy for implant with high corrosion resistance and prompt bone connectivity

由于钛具有优异的耐腐蚀性和生物相容性，作为活体的金属材料，它被用于人工髋关节和牙科植入物等。与其他材料相比，钛与骨的相容性更好。本研究的目的是发展钛种植体的表面改性方法，使钛种植体获得坚固、迅速的骨性，有一种方法调用碱处理，使预期的表面改性方法之一直接在钛表面提取一层骨状磷灰石层。材料被浸泡在模拟体液中，钛的生物活性取决于其上是否有磷灰石析出。为了预先在钛表面固定少量钙，本研究在200℃下采用10 mmol/L CaCl2溶液进行水热处理，考虑到磷灰石在体内的生成机理。纯钛及钛合金经此处理后，大鼠骨髓成骨细胞的初始贴壁率和增殖速度均高于碱处理。将经此处理的钛种植体植入大鼠胫骨内，观察到骨与种植体的界面。种植1周后，钛的骨接触率达到55%以上，而未处理的钛的骨接触率为5.7%。从上述结果来看，用CaCl2溶液进行水热处理是一种赋予钛生物活性的表面改性方法。

Because titanium has an excellent corrosion resistance and a biocompatibility, it is used for an artificial hip joint and a dental implant, etc. as a metallic material for the living body. The compatibility of titanium with the bone is more excellent than that of other materials. However, there is a case removed after implantation by the micro movement etc. The aim of this research is a development of surface modification method for the titanium implant to give a strong and prompt bone.There is a method of calling the alkali treatment to make one of the expected surface modification method extract a bone-like apatite layer directly to the surface of titanium. The material is soaked in a simulated body fluid, and the bioactivity of titanium is appreciable according to whether apatite precipitate on it.In this study, in order to fix a small amount of Ca to the surface of titanium beforehand, a hydro-thermal treatment was given at 200C by using 10mmol/L CaCl_2 solution paying attention to the generation mechanism of apatite in vivo. Pure Ti and the Ti alloy with this treatment showed that an initial attachment and a proliferation speed of the osteoblast cell gathered from rat's bone marrow were higher than those with the alkali treatment.The titanium implant with this treatment was implanted in rat's tibia bone and interface of bone and implant was observed. After implantation for 1 week, the bone contact rate of the titanium with this treatment indicated the more than 55% while the titanium with non-treatment indicated 5.7%. And that value reached about 100% after implantation for 4 weeks.From the above-mentioned result, it was suggested that the hydro-thermal treatment that used the CaCl_2 solution was a surface modification method giving bioactivity for titanium.