不同种植体外形设计对上颌窦提升术后种植体周围应力分布的影响

Biochemical analysis of stress distribution of dental implants with different body shapes after maxillary sinus augmentation

目的:比较不同种植体外形设计对上颌窦提升术后种植体周围生物力学的影响。方法:在D3型上颌骨简化模型上利用三维有限元法分析3种不同外形设计的种植体在植骨与不植骨条件下的应力分布情况。假设所有材料都是线弹性、连续材料,向种植体施加150 N的倾斜力,测量种植体周围骨组织的最大等效力(equivalent von-Mises,EQV)。采用Ansys Workbench 14.5软件包对数据进行测量分析,采用SPSS 17.0软件包对数据进行统计学分析。结果:各组应力集中区域均位于种植体颈部皮质骨区域。不同种植体外形设计对种植体周围皮质骨最大EQV值无显著影响,但锥形种植体较其他种植体的周围松质骨最大EQV值显著上升,上颌窦提升术后植骨可以降低各组种植体周围最大EQV值。结论:锥形种植体用于上颌后牙区种植修复时,可能引起种植体周围松质骨应力变大,增加种植体周围骨吸收的风险。上颌窦提升后植骨,可降低种植体周围压力负载。

PURPOSE:To compare the stress distribution of dental implants with different body shapes after maxillary sinus augmentation.MRTHODS:Three different implant models varying in implant shape were investigated in D3-type maxilla.All materials were assumed to be linear elastic,homogenous and isotropic.An oblique force of 150 N was applied to the implant.Maximal equivalent von-Mises of supporting bone around implants were measured.All of the models were measured by Ansys Workbench 14.5.Statistical analysis was performed using SPSS 17.0 software package.RESULTS:Highest stress of supporting bone emerged on the crestal cortical site around the implant neck.There was no significant difference in the maximum EQV of supporting cortical bone between different groups;the maximum EQV of supporting trabecular bone in the tapered implant group was much higher than other groups;application of grafts reduced the maximum EQV of both cortical and trabecular bone in all groups.CONCLUSIONS:Tampered implant can induce elevated stress distribution of the upper trabecular bone,which may promote marginal bone loss.Application of grafts after maxillary sinus augmentation could favors in reducing the stress loading of dental implants.