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

在Ti-29 Nb-13 Ta-4.6Zr合金上放置60 CaO-30P_2O_5-7Na_2O-3TiO_2（摩尔%）的玻璃母粉，在空气中800℃加热1h，可实现含β-Ca_3（PO_4）_2晶体的生物活性钙磷转化玻璃陶瓷与β-钛相的牢固连接;拉伸连接强度估计平均为1.26MPa。在加热过程中，在金属基底上形成了成分梯度层。玻璃陶瓷与金属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面氧化物相的反应控制的，在模拟体液（SBF）中浸泡20天后，在玻璃陶瓷上观察到骨状磷灰石的形成。我们发现，在水中进行压热处理可以很容易地提高微晶玻璃形成磷灰石的能力。当高压灭菌的样品浸泡在SBF中时，3天后开始形成骨样磷灰石。另一方面，即使在SBF中浸泡10天，在未进行高压灭菌的玻璃陶瓷上也没有磷灰石形成。在热压过程中，钛离子在表面周围的非晶相中形成非晶相和水合二氧化钛基团，这可能在磷灰石的形成中起重要作用。将经处理的钛合金棒样品植入家兔股骨中。植入4周后，样品周围可见新形成的骨，它们直接接触，无纤维组织。

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.