种植体直径-长度比的三维有限元应力分析

目的:探讨直径与长度连续变化时选择种植体尺寸的方法。方法 :运用Pro/E和ANSYS软件建立不同长度(7¹6 mm)、不同直径(316 mm)、不同直径(3⁶ mm)的三维有限元模型,施加垂直荷载和侧向荷载,观察种植体位移峰值和骨组织VonMises应力峰值等评估指标。结果:垂直或侧向荷载作用下,随着直径和长度的增大,各评估指标均明显下降(60%6 mm)的三维有限元模型,施加垂直荷载和侧向荷载,观察种植体位移峰值和骨组织VonMises应力峰值等评估指标。结果:垂直或侧向荷载作用下,随着直径和长度的增大,各评估指标均明显下降(60%⁸0%),相关度分析显示,两种荷载下直径的影响均较大(约90%),长度的影响与荷载有关(垂直荷载:18%80%),相关度分析显示,两种荷载下直径的影响均较大(约90%),长度的影响与荷载有关(垂直荷载:18%⁶0%;侧向荷载:<7%)。直径-长度比兼顾种植体直径与长度,当确定皮质骨承载力及安全系数,便可由直径-长度关系曲线选择合适的种植体直径与长度。结论:种植体直径与长度均可明显影响种植体位移和骨组织应力峰值。本文介绍的直径长度比法可为临床医生选择、优化种植体提供一种新的思路。

Finite Element Analysis of Different Diameter to Length Ratio in Dental Implants

Objective： The aim of this study was to discuss the methodology of selecting implant with continuous changes of diameter and length. Methods： The Pro/engineering software was used to created 3-D models of dental implants with different diameters（3 mm~6 mm） and length（7 mm~16 mm）, being assembled to 3-D models of mandible bone segments,which were imported into ANSYS finite element analysis software and meshed to create finite models. The values of dis-placement and Von-Mises stress of implant and bone were obtained, after models were loaded with vertical force and oblique load. Results： After models were loaded both by vertical and oblique loads, with the increase of implant diameter and length, the values of each evaluation indicators were significantly reduced（60%~80%）. Effect of implant diameter was more significant（≈90%）, the implant length was related to the types of loading（vertical force： 18%~60%; oblique load： 7%）. The ratio construed by diameter and length was used for the selection of dental implants when safety factor was de-termined. Conclusion： Increasing the implant diameter and length can significantly reduce the displacement of implant and stress of bone tissue. Introduction of methodology of diameter-length ratio establishes a new practical and effective method for implants selection in clinical practices.