背景:增材制造(AM)技术帮助实现了医疗领域的若干进步,特别是就植入物的制造而言。但由于直接金属激光烧结(DMLS)接骨板的力学性能不确定,其应用相当有限。这项研究的目的是表征抛光的DMLS重建板的生物力学特性,并将这些特性与常用植入物的特性进行比较,并发现DMLS板的机械性能是否满足临床应用的要求。
方法:在本研究中,我们通过DMLS和计算机数控(CNC)技术制造了两组板材。之后,我们抛光了所有的样品并调查了它们的粗糙度,组件,硬度,静态弯曲,和扭转性能。此外,进行了循环弯曲试验和断口分析。通过单调测试数据对该组进行统计比较,并进行了定性比较以评估疲劳故障。
结果:我们发现抛光后的表面粗糙度或组件没有差异,但DMLS板的硬度比CNC板的硬度大7.42%(p<0.01)。与数控板相比,DMLS板的静态弯曲和扭转性能明显更大。在动态测试中,DMLS板在0.6、0.8、0.9和1kN循环载荷下经受了106、106、32,731和33,264个循环,分别,而CNC板存活了106、106、106和283,714个循环。
结论:这些结果表明DMLS板的机械性能更强,疲劳试验下的强度是足够的。DMLS植入物具有巨大的潜力,可能成为未来临床使用的更好选择。然而,在手术室中直接应用这些AM仪器需要进一步验证,包括动物和临床实验。
BACKGROUND: Additive manufacturing (AM) technology has helped to achieve several advances in the medical field, particularly as far as fabrication of implants is concerned. But the application of direct metal laser sintering (DMLS) bone plate is quite limited due to the indeterminate mechanical property. The purposes of this
study were to characterize the biomechanical properties of the polished DMLS reconstruction plate and to compare these with the properties of commonly applied implants and to find whether the mechanical performance of DMLS plate meets the requirements for clinical application.
METHODS: In this
study, we fabricated two groups of plates by DMLS and computer numerical control (CNC) techniques. After that, we polished all samples and investigated their roughness, components, hardness, static bending, and torsional performance. Moreover, cyclic bending tests and fractographic analysis were conducted. Statistical comparisons of the group by means of monotonic test data were made, and a qualitative comparison was performed to assess failures in fatigue.
RESULTS: We found no differences in surface roughness or components after polishing, but the DMLS plate hardness is 7.42% (p < 0.01) greater than that of the CNC plates. Compared with the CNC plates, the DMLS plate static bending and torsional performance were significantly greater. In a dynamic test, the DMLS plates survived 106, 106, 32,731, and 33,264 cycles under 0.6, 0.8, 0.9, and 1 kN cyclic loads, respectively, while the CNC plates survived 106, 106, 106, and 283,714 cycles.
CONCLUSIONS: These results indicate that the mechanical performances of the DMLS plate are stronger, and the strength under fatigue tests is sufficient. DMLS implant has great potential and may become a better choice for clinical use in the future. However, direct application of these AM instruments in the operating room requires further validation including animal and clinical experiment.