Improvement of the balance between a reduced stress shielding and bone rit ingrowth by bioactive coatings onto porous titanium substrates
Improvement of the balance between a reduced stress shielding and bone rit ingrowth by bioactive coatings onto porous titanium substrates
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DOI：
10.1016/j.surfcoat.2018.01.019
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发表时间：
2018-03-25
影响因子：
5.4
通讯作者：
Torres, Yadir
中科院分区：
文献类型：
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作者：
Dominguez-Trujillo, Cristina;Ternero, Fatima;Torres, Yadir
商业纯钛被认为是皮质骨组织的良好替代品。然而，应力屏蔽和骨整合不足仍然是一些需要解决的局限性。在本研究中，采用空间支架技术（50 vol%的NH4HCO3，粒径在250 ~ 355 μ m之间）制备多孔钛基板。得到的试件刚度和屈服强度与皮质骨组织基本一致。采用滴落法在基底上涂覆三层生物玻璃（圆）45S5 (BG)，这是一种新的经济技术。通过阿基米德方法、图像分析、x射线显微计算机断层扫描和激光共聚焦显微镜对孔隙率和表面进行表征，并通过超声技术、单轴压缩和微力学测试对其力学行为进行分析。对涂层的均匀性、渗透效率和完整性进行了评价。涂层在多孔钛基体上的附着力优于在全致密钛基体上的附着力。最后，通过模拟体液浸泡测定BG涂层的生物活性。利用扫描电镜和x射线衍射分析研究了羟基磷灰石在基体上的形成和生长过程。结果表明，在包覆的全致密和多孔样品中均可形成羟基磷灰石。这些特征表明这种承载钛种植体的骨整合性得到了改善。
Commercial pure titanium is known as good substitute for cortical bone tissue. Nevertheless, stress-shielding and the lack of osseointegration are still some limitations to solve. In this study, porous titanium substrates were manufactured by space-holder technique (50 vol% of NH4HCO3 with particle size between 250 and 355 mu m). The obtained stiffness and yield strength of specimens were compatible with cortical bone tissue. The substrates were coated with three layers of Bioglass(circle) 45S5 (BG) by dripping sedimentation, a new and economic technique. The porosity and surface characterization were performed by Archimedes' method, image analysis, X-ray micro computed tomography and confocal laser microscopy, while the mechanical behavior was analyzed by ultrasound technique, uniaxial compression and micro-mechanical testing. Homogeneity, infiltration efficiency and coating integrity were evaluated. The adhesion of the coating was better on porous titanium substrates than on full dense ones. Finally, the bioactivity of the BG coating was determined via immersion in Simulated Body Fluid. The formation and growth of hydroxyapatite on the substrate were studied by scanning electron microscopy and X-ray diffraction analysis. The results showed hydroxyapatite formation in both coated full dense and porous samples. These features indicate the improvement of osseointegration for this sort of load bearing Ti implants.