水热处理镁离子改性改善纯钛骨传导性的研究

Improved osteoconductivity of pure titanium modified with Magnesium byhydrothermal treatment

摘要:

在200℃,0.1mol/L的MgCl₂溶液中对纯钛进行了水热处理,以期改善其生物活性。采用多种分析手段对水热处理前后试样的形貌、粗糙度、润湿性能及表面化学成分进行了分析；采用模拟体液浸泡法评价了处理前后试样的体外骨传导性。水热处理在试样表面形成了纳米氧化钛颗粒,但并没有改变试样的微米尺度的形貌,经过水热处理的试样表现出了超亲水性。水热处理成功地将Mg元素复合至钛表面；在MgCl₂溶液中进行水热处理时,Mg元素主要以钛酸镁形式存在,而在pH为9.5的MgCl₂的溶液中进行水热处理时,Mg元素主要以Mg(OH)₂形式存在。在SBF中浸泡3天后,水热处理试样表面即可观察到典型的羟基磷灰石球状晶簇,而未经处理的试样表面则未能发现沉积,此外,过高的Mg复合量抑制了羟基磷灰石的形核长大。结果表明,水热处理在保持种植体宏观形貌不受影响的前提下可作为种植体生产的最后工序以提高其骨结合性。

Abstract:

Pure titanium was hydrothermally treated in 0.1 mol/L MgCl₂ solutions with different pH at 200°C for 24hr in order to improve its bioactivity. Surface morphology, roughness, wettability and chemical composition were characterized with sophisticated equipment before and after treatment. Simulated body fluid immersion experiment was conducted to examine in vitro osteoconductivity. Hydrothermal treatment preserved the macro topography of polished substrates in spite nano-sized precipitations were observed and these surfaces showed superhydrophilicity. Magnesium titanate was formed on titanium surface after hydrothermal treatment in MgCl₂ solution, however, under high pH, Mg(OH)₂ precipitated from the solution. Typical apatite spheres were observed on hydrothermally treated samples after immersion in SBF for 2 days. However, the precipitation was depressed with increasing Mg amount incorporated into titanium surface. The hydrothermal treatment was a promising finial treatment for fabricating titanium implants with good bioactivity.