Abstract: Objective:  To examine the physico-chemical properties and their influences to osteointegration of Ti implants due to surface modified by laser micro-arc oxidation (MAO). Methods: 16 threaded cylindrical implants were manufactured from rods of commercially pure titanium. 8 pure titanium machined surface implants were used as control group and other 8 implants which surface modified by laser-micro-arc oxidation as experimental group. Physico-chemical properties were examined by the energy dispersive spectrum (EDX), scanning electron microscopy (SEM), and Veeco roughness measurement. Ti implants were embeded on the tibia of New Zealand rabbits randomly. The rabbits were sacrificed and the tibia were retrived for observation at 2-, 4- and 6- week respectively. To evaluate the mineralization ratio, the rabbits were injected tetracycline subcutaneously at 13- day and 14- day before sampling and were injected calcein subcutaneously at 3- day and 4- day before sampling. All samples were processed for undecalcified ground sectioning. Bone implant contact (BIC) along the entire implant was calculated. Results: It was evident that implant surface in experiment groups covered with micro pores. The aperture is about 100 μ m, hole depth was 40~80 μm. MAO surface has many microporous structure. The micro hole diameter was about 1~5 μm, in which there were more small level micro hole with diameter less than 1 μm. The Ra value of control group was 179.23 nm, The Ra value of experimental group was 1.55 μm. The control group was composed of Ti elements, the experimental group was composed of Ti, 0, Ca, and P elements. The mineralization ratio between the two groups was statistically difference (P<0.05), so as the contact ratio of osseo-implant interface (OI values). Conclusion: The microporous structure of MAO coating was formed in pure titanium implant surface through the laser-micro-arc oxidation,which has the good biocompatibility and bone conductivity, can promote osteointegration on implant surface.

Key words:  titanium, micro-arc oxidation, laser, implant, osteointegration, rabbit

摘要： 目的： 对比机械光滑表面和经激光-微弧氧化处理表面的纯钛种植体的理化性能，及其对早期骨结合的影响。方法： 将纯钛棒加工制作成16颗螺纹柱形种植体，对照组（光滑组）为机械加工光滑表面种植体8颗，实验组（激光-微弧氧化组）为经激光-微弧氧化处理种植体8颗。通过能谱分析仪（EDX）和扫描电镜（SEM）分析种植体表面性质，Veeco粗糙仪检测其粗糙度（Ra）。分别将16颗种植体随机植入新西兰兔的胫骨， 4周后处死取样，处死前第13天和第14天皮下注射四环素，处死前第3和第4天皮下注射钙黄绿素，通过四环素－钙黄绿素双色标记示踪检测其矿化速率。将标本通过塑料包埋制作成不脱钙含种植体骨切片，观察种植体-骨界面的骨结合情况。结果： 实验组表面可见较大级别微孔，基本与激光处理后一致，孔径约100 μm，孔深40～80 μm。种植体表面微弧氧化膜具有多微孔结构，微孔孔径约1～5 μm，微孔内还可见更小级别微孔，孔径小于1 μm。对照组种植体表面Ra值为0.179 μm，实验组表面的微弧氧化膜Ra值为1.55 μm。对照组只检测到Ti元素，实验组钛表面氧化膜层中含Ti、O、Ca、P元素。实验组的矿化速率和种植体与骨接触的百分率（OI值）均显著高于对照组（P<0.05）。结论：通过激光-微弧氧化表面处理，纯钛种植体表面形成多层次多微孔的微弧氧化膜，具有良好的生物相容性和骨引导性，能促进种植体骨结合。

关键词: 钛；  , 微弧氧化；  , 激光；  , 种植体；  , 骨结合；  , 兔

CLC Number: 

• R782.13