不同厚度的个性化镁合金网的有限元分析

Finite element analysis of individualized magnesium alloy meshes with different thickness

目的利用三维有限元分析不同厚度镁合金网在骨愈合过程中的应力应变分布,从生物力学角度为个性化镁合金网的设计提供参考。方法提取下颌骨CBCT数据,重建C2-D2骨缺损区三维模型,设计骨植入材料及不同厚度镁合金网的三维有限元模型,分析其应力应变分布。结果镁合金网的应力应变随着厚度的增加而减小。骨愈合进程中骨植入材料的应力逐渐增大应变逐渐变小,不成熟骨及成熟骨的应变均小于断裂应变。镁合金网降解的过程中应力先减小后增大。结论0.3 mm、0.4 mm厚度镁合金网负荷承载能力较小,不能满足较大面积引导骨再生的需求。0.5 mm厚度镁合金网的最大等效应力在安全范围内,在降解的过程中强度足够,能引导良好的骨愈合,可满足临床需要。

Objective To investigate the stress-strain distribution of magnesium alloy meshes with different thickness during bone healing by three-dimensional finite element analysis in order to provide a reference for the design of personalized magnesium alloy mesh.Methods After the cone-beam computed tomography(CBCT)data of a patient with tooth loss of C2-D2 and large alveolar defect were extracted,three-dimensional reconstruction was performed on the bone defect area.Three-dimensional finite element models of bone implant material and magnesium alloy meshes with different thickness were designed,and their stress-strain distributions were analyzed.Results The strain and stress showed a decreasing trend with the increase of the thickness of magnesium alloy mesh.During the process of bone healing,the stress of the bone implant material was gradually increased while the strain was gradually decreased.The strain of immature and mature bone was less than the strain at break.The stress was decreased first and then increased in the degradation of magnesium alloy mesh.Conclusion Magnesium alloy mesh of 0.3 and 0.4 mm thickness can only bear a small load,and can’t meet the need of large area guided bone regeneration(GBR).The maximum equivalent stress of 0.5 mm-thickness magnesium alloy mesh is within the safe range,and the mesh has enough strength in the process of degradation,and can guide good bone healing and meet the clinical needs of GBR.