包含直径和长度连续变化种植体骨块三维有限元模型的建立

Establishment of three dimensional finite element models of continuous implant with diameter and length variation

目的:利用计算机辅助设计软件与三维有限元分析软件的参数双向传递功能,建立包含直径和长度连续变化的种植体骨块三维有限元模型。方法:实验于2005-03/08在西安理工大学机械与精密仪器工程学院完成。①CAD(ComputerAidedDesign)计算机辅助设计软件(Pro/EWidefire2.0,ParametricTechnologyCorporation,USA)。AnsysWorkbench10.0有限元分析软件(SASIP,Inc,USA)。②应用CAD软件在计算机上建立包含修复体上部结构和种植体的下颌后牙区骨块。以第一前磨牙的横断切面作为基底面,将其进行近远中的拉伸形成三维的下颌骨骨块。牙槽嵴顶的皮质骨厚度变化为1.9～3.1mm,松质骨的近远中未被皮质骨包绕。模拟一圆柱形种植体,同时模拟高5mm的基台,基台和种植体简化为一个整体,在基台上模拟2mm厚的瓷修复体。设定种植体直径(D)和种植体长度(L)为变量,D变化范围为2.5～5.0mm,L变化范围为6.0～16.0mm。建成后三维有限元模型与实体组织具有良好的几何相似性,利用AnsysWorkbench10.0软件中的Mesh命令,直接对模型进行智能网格划分,进行有限元分析。结果:在直径为3.5mm、长度为13.0mm时的颌骨VonMises应力分布云图上,VonMises峰值位于种植体颈部密质骨区。结论:应用AnsysWorkbench软件与CAD软件的参数双向传递的功能,使得种植修复中种植体直径和长度均连续变化的三维有限元模型建立得以实现。

AIM： To construct continuous implant diameter and length variation throe dimensions （3D） finite element models by computer aided design （CAD） software and bidirectional parameter transmit of 3D finite element analysis software. METHODS： The experiment was performed at the Institute of Mechanism and Precision Instrument, Xi＇an University of Technology from March to August 2005. ①CAD software （Pro/E Widefire 2.0, Parametric Technology Corporation, USA）, Ansys Workbench 10.0 finite element analysis software （SAS IP, Inc, USA） ware applied. ②A posterior mandible segment with an implant and a superstructure were modeled on a personal computer with CAD software. A crosssection of a mandible in the first premolar region was used as a basis for a solid model, and then the cross-sectional image was extruded to create a three-dimensional mandible segment. The thickness of cortical bone in the crest region varied from 1.9 mm to 3.1mm, and the me, sial and distal section planes ware not covered by cortical bone. A cylindrical implant and a 5 mm high solid abutment ware modeled and ware simplified to one unit. A porcelain superstructure with 2 mm occlusal thickness was applied over the titanium abutmen, The diameter of implant （D） and length of implant （L） ware set as the input variables. D ranged from 2.5 to 5.0 mm, and L ranged from 6.0 to 16.0 mm. The 3D models ware geometric similar with mandible section with implant. The models ware meshed and analyzed in Ansys workbench10.0 software automatically. RESULTS ： Under lateral load, when D was 3.5 mm and L was 13.0 mm, the highest Von Mises stress was observed bucoally and lingually near the implant neck in cortical bone. CONCLUSION： Continuous implant diameter and length changing 3D finite element models can be rebuilt by bidirectional parameter transmit of Ansys workbench software and CAD software.