Yokoyama Ken'ichi, Ichikawa Tetsuo, Murakami Hiroki, Miyamoto Youji, Asaoka Kenzo
Department of Dental Engineering, School of Dentistry, Tokushima University, Japan.
Biomaterials. 2002 Jun;23(12):2459-65. doi: 10.1016/s0142-9612(01)00380-5.
Titanium and its alloy are increasingly attracting attention for use as biomaterials. However, delayed fracture of titanium dental implants has been reported, and factors affecting the acceleration of corrosion and fatigue have to be determined. The fractured surface of a retrieved titanium screw and metallurgical structures of a dental implant system were analyzed. The outer surface of the retrieved screw had a structure different from that of the as-received screw. It was confirmed that a shear crack initiated at the root of the thread and propagated into the inner section of the screw. Gas chromatography revealed that the retrieved screw had absorbed a higher amount of hydrogen than the as-received sample. The grain structure of a titanium screw, immersed in a solution known to induce hydrogen absorption, showed features similar to those of the retrieved screw. It was concluded that titanium in a biological environment absorbs hydrogen and this may be the reason for delayed fracture of a titanium implant.
钛及其合金作为生物材料越来越受到关注。然而，已有报道称钛牙种植体存在延迟断裂的情况，因此必须确定影响腐蚀和疲劳加速的因素。对一枚取出的钛螺钉的断裂表面和一个牙种植体系统的金相结构进行了分析。取出的螺钉外表面结构与接收时的螺钉不同。经证实，一条剪切裂纹在螺纹根部萌生并扩展至螺钉内部。气相色谱分析表明，取出的螺钉比接收时的样品吸收了更多的氢。将一枚钛螺钉浸泡在已知会诱导氢吸收的溶液中后，其晶粒结构呈现出与取出的螺钉相似的特征。得出的结论是，钛在生物环境中会吸收氢，这可能是钛种植体延迟断裂的原因。
