选择性激光熔覆制备微孔钛试件及体内实验研究

Study of porous titanium specimens manufactured by selective laser melting in vivo

目的评估选择性激光熔覆(SLM)成形微孔钛结构对材料生物活性的影响。方法以0~45μm的球形二级钛粉为实验原料,平铺在5 cm×5 cm×0.5 cm的纯钛基板上,在合适的激光参数条件下,制备出孔径范围在150~200μm及200~250μm的两组试件。以大颗粒喷砂酸蚀(SLA)工艺处理的试件为对照,通过动物实验研究,评价材料生物活性。结果场发射扫描电镜观察不同试件表面微孔结构,EDS显示SLA组表面C元素高于SLM组(P=0.037);SLM组试件弹性模量明显降低,接近于人类骨皮质(P<0.05);孔径200~250μm试件骨结合率在第8周差异有统计学意义(P=0.028)。结论微孔结构能有效降低试件表面的弹性模量,且孔径范围200~250μm的试件在中期诱导骨形成的能力上更加显著。

Objective To evaluate the effect of bioactivity of porous titanium specimens manufactured by selective laser melting（ SLM）. Methods Spherical titanium powder in 0 ~ 45 μm was used as the experimental materials and formed on a pure titanium substrate of 5 cm × 5 cm × 0. 5 cm. Under suitable laser parameters,the pore size range was 150 ~ 200 μm and 200 ~ 250 μm of the two sets of specimens. Sandblasting with large-grit and acid-etching（SLA） was used as the control group,and the related properties were evaluated by the relatedanimal experiments.Results Field emission scanning electron microscopyobservation of different surface of pore structure. The EDS showed that the C element on the SLA group was higher than that of the SLM group（ P = 0. 037）. The elastic modulus of the SLM group was significantly lower than that of the human bone cortex（ P〈0. 05）. The macroporous implant could promote the growth of bone tissue（ P = 0. 028）. Conclusion The microporous structure can effectively reduce the elastic modulus of the specimen surface,and the pore size range of 200 ~ 250 μm specimen in the middle of the ability to induce bone formation is more significant.