Ti-75合金作为复合种植体基底材料的实验研究

Experimental study of Ti-75 alloy as a substrate of composite implant

目的：观察复合种植体（ＣＩ）基底材料Ｔｉ－７５合金（ＴＡ）的生物学特性和ＴＡ－涂层结合强度在种植体骨界面结合强度中的表现。方法：应用穿皮质骨种植模型，在双侧犬股骨内种植ＴＡ和ＣＩ共３２枚；在术后３个月和６个月，处死动物取材；种植体骨界面进行组织学观察和推出试验，并对断裂后的种植体骨界面进行扫描电镜观察。结果：ＴＡ与ＣＩ均与骨组织形成了骨性结合；ＣＩ骨界面的剪切强度高于ＴＡ（Ｐ＜０．０１）；ＣＩ骨界面断裂大部分在涂层骨组织界面和涂层内部，很少在涂层ＴＡ界面。结论：ＴＡ与ＣＩ均具有良好的生物相容性；ＴＡ涂层界面具有足够的结合强度，是值得进一步研究的复合种植体基底材料。

Objective:To evaluate the biocompatibility of Ti-75 alloy(TA) as a substrate of composite implant (CI) and the role of the shear strength of TA-coating in the CI-bone interface. Methods:A transcortical implant model was used. A total of 32 implants of CI and TA were implanted into bilateral femur of 4 adult mongrel dogs. the animals were killed 3 and 6 months after surgery. The implant-bone interfaces were observed by morphological examination and the interface shear strength was measured by push-out test. After push-out test, the failure interfaces were observed by SEM. Results:Osseo-integration was confirmed in the both interfaces of CI and TA with bone. The interface strength(MPa) of CI in 3 and 6 month was 7. 84± 0.99 and 12. 76± 1. 45, that of TA 3. 71± 1. 10 and 6. 33± 0. 89 respectively (P<0.01). The failure interfaces of CI-bone were major in the coating-bone and within the coating, only a little failure interface of coating-TA were visible. Conclusion:TA and CI are biocompatible. CI has stronger shear strength with coating than TA, and may be used as a substrate of composite implant.