Development of surface modification technology of titanium alloys for artificial bones using phosphate glasses

将含有β-Ca_3(PO_4)_2晶体的生物活性磷酸钙倒置玻璃陶瓷与含有β-钛相的Ti-29Nb-13Ta-4.6Zr合金加热，在800℃空气中放置成分为60cao - 30p_2o_5 - 7na22o - 3tio_2（摩尔%）的母玻粉1 h，可以牢固地结合；拉伸连接强度平均为~ 26MPa。在加热过程中，金属基体上形成了一层成分梯度层。玻璃陶瓷与金属之间的连接是由玻璃陶瓷中玻璃相的粘性流动和玻璃相与金属表层周围形成的氧化相的反应控制的。在模拟体液（SBF）中浸泡20天后，观察到玻璃陶瓷表面形成骨状磷灰石。我们发现，在水中进行高压灭菌处理可以很容易地提高玻璃陶瓷的磷灰石形成能力。蒸压后的样品在SBF中浸泡3天后，骨状磷灰石开始形成。另一方面，即使在SBF中浸泡10天，未进行高压灭菌的玻璃陶瓷上也没有形成磷灰石。在高压灭菌过程中，钛离子在表面周围的无定形相中形成锐钛矿相和水合钛基团，这可能在磷灰石的形成中起重要作用。将处理后的钛合金棒状试样植入兔股骨。植入4周后，样品周围可见新形成的骨，它们直接接触，没有纤维组织。

A bioactive calcium phosphate invert glass-ceramic containing β-Ca_3(PO_4)_2 crystals could be joined strongly with a Ti-29Nb-13Ta-4.6Zr alloy consisting of a β-titanium phase by heating the metal, on which the mother glass powders with a composition 60CaO-30P_2O_5-7Na_2O-3TiO_2 in mol% were placed, at 800℃ for 1 h in air ; the tensile joining strength was estimated to be 〜26MPa on average. A compositionally gradient layer was developed on the metallic substrate during the heating. The joining between the glass-ceramic and the metal is suggested to be controlled by viscous, flow of the glassy phase in the glass-ceramic and by reaction of the glassy phase with the oxide phase formed around the surface layer of the metal.Bonelike apatite formation was observed on the glass-ceramic after 20 days of soaking in simulated body fluid (SBF). We found the apatite-forming ability of the glass-ceramic can be easily improved by autoclaving treatment in water. When the autoclaved sample was soaked in SBF, bonelike apatite began to form after 3 days. On the other hand, no apatite formed on the glass-ceramic, which was not autoclaved, even by soaking in SBF for 10 days. During the autoclaving, titanium ions in the amorphous phases around the surface form anatase phase and the hydrated titania groups, which may play an important role in the apatite formation.. A rod sample of the treated titanium alloy was implanted into a femur of rabbit. After 4-week implantation, newly formed bones were seen around the sample and they contacted directly without fibrous tissue.