不同表面形貌掺锶羟基磷灰石涂层钛种植体的体内实验研究

目的:观察不同微弧氧化时间处理对纯钛表面形成的掺锶羟基磷灰石涂层表面形貌的影响,以及不同表面形貌特征对其表面成骨特性的影响。方法:经5、10、15 min 3种微弧氧化时间在钛表形成3组掺锶羟基磷灰石涂层,分别采用扫描电镜观察表面形貌;采用表面粗糙度仪测量涂层表面粗糙度数值。然后再将3种钛种植体植入新西兰兔体内,术后4、12周取材,采用组织染色法观察植入体表面骨形成情况和骨接触率(Bone Implant Contact,BIC)。结果:随着微弧氧化时间的延长,涂层表面形貌成多孔状且越加不规则,粗糙度增加;丽春红染色显示4周时植入体表面有新骨形成,12周时转化为成熟的骨组织并与涂层形成紧密的骨结合。随植入时间的延长种植体表面骨接触率逐渐增加,而且15 min组和10 min组的骨接触率在第4周和12周均高于5 min组。结论:不同微弧氧化时间可以改变掺锶羟基磷灰石涂层的表面特性,而粗化的的涂层表面结构有利于骨组织的形成。

In vivo fixation of strontium-substituted hydroxyapatite titanium implants with increased surface roughness

AIM: To examine the surface properties of strontium-substituted hydroxyapatite titanium implants made by micro-arcoxidation(MAO)through different oxidation time,and the effects of the coatings on new bone formation and bone-implant bonding in vivo.METHODS:Sr-HA coated titanium implants were manufactured by MAO with different oxidation time(5 min,10 min and 15 min).The surface morphology was observed by scanning electron microscope(SEM).Surface roughness was measured using a surface roughness measuring system.Twenty-four implants were inserted into the rabbit femurs.After implantation of 4 and 12 weeks,the morphology of the bone-implant interfaces was evaluated by histological examination.RESULTS:The Sr-HA coating showed a microporous structure.With the increase of oxidation time,the surface morphology of the implants became more irregular,surface roughness was enhanced.Histomorphological analysis showed that 10 min and 15 min Sr-HA coating exhibited osteogenic activity at the early stage of bone healing period.The quantity and density of newly formed bone around the implant were much greater than those in the 5 min Sr-HA group,and bone implant contacts(BICs) were significantly higher than that in the 5 min Sr-HA group.CONCLUSION: Extending the oxidation time can alter the surface properties of Sr-HA coating.The surface roughness of titanium is a factor which promotes new bone formation and osseointegration at the interface of the bone implants.