不同植入方向微型种植体支抗的三维有限元分析  

Three-dimensional finite element analysis of anchorage micro-implant with different embedding directions

作　　者：王汉思[1] 李晓智[1] 李康宁[2] 曾明慧[1] 何艳[1] 

机构地区：[1]重庆医科大学附属第一医院口腔矫形科,重庆400016 [2]解放军后勤工程学院流体力学教研室,重庆400016

出　　处：《第二军医大学学报》2008年第7期829-832,共4页Academic Journal of Second Military Medical University

摘　　要：目的:建立简化的微型种植体-骨三维有限元模型,研究不同植入方向下微型种植体-骨界面的生物力学变化,为微型种植体的临床应用提供理论依据。方法:应用I-DEAS有限元分析软件,将微型种植体以30°角倾斜植入骨块,在保持加载力方向、微型种植体与植入处骨表面夹角不变的情况下,以植入点为圆心,微型种植体在骨平面上的投影线为半径水平旋转180°,设定0°、45°、90°、135°、180°共5个植入方向。在与植入处骨表面平行的200g力作用下,分析微型种植体-骨界面的应力分布及位移变化。结果:各组应力值及位移值的变化均符合临床生理要求,微型种植体的植入区、骨皮质区应力相对集中,Von-mises应力、拉应力、压应力分布变化总体一致,应力曲线整体呈递减趋势。在脱位力作用下,0°、45°组应力值小于其他组,0°组应力值最小,0°、45°组位移值明显高于90°、135°、180°组,90°组的位移值最小。结论:不同植入方向的微型种植体可以安全承载与植入处骨表面平行的200g正畸力。临床上选择微型种植体植入方向时,尽量减小加载力对其的脱位作用,才更有利于微型种植体的稳定。Objective： To establish a simplified three-dimensional finite element model of orthodontic anchorage microimplant, and to study the biomechanical changes of the micro-implant-bone interface when embedded in different directions, so as to provide a theoretical basis for clinical application of the micro-implant. Methods： I-DEAS finite element analysis software was used to establish a micro-implant and bone finite element model. The micro-implant was embedded into the bone at an angle of 30°. The orientation of the loading force and the embedding angle were kept unchanged; using the embedded point as the center of a circle and the projective line of micro-implant on the bone surface as the radius, 5 different embedding directions,including 0° ,45°, 90°, 135° and180v, were chosen. A simulated orthodontic force of 200 g was loaded parallel to the surface of bone in the embedded region, and the stress distribution and displacement changes on the micro-implant-bone interface were analyzed. Results：The changes of stresses and displacement were within the clinicophysiological range in all groups. The embedded region of micro-implant and the cortical bone were stress-focused areas. The changes of Von-mises stress, stretching stress and compressive stress were largely the same; the stress distribution had a decreasing tendency. Under retentive force,the stresses of group 0° and 45° were smaller than those of the other groups,with group 0° having the smallest one. The displacement of group 0° and 45° were evidently larger than those of group 90°, 135° and 180°, with that of group 90° having the smallest one. Conclusion：The micro-implant embedded with different directions can safely bear 200 g force parallel to the surface of bone in embedded region. When choose the embedding directions of micro-implant, efforts should be made to reduce the retentive effect of the loaded force to keep the stability of micro-implant.

关 键 词：牙种植体 有限元分析 生物力学 植入方向 

分 类 号：R783.5[医药卫生—口腔医学]