摘要
目的:探讨圆柱状V形螺纹种植体螺纹参数变化对骨组织应力大小的影响,为临床设计和选择最佳的螺纹参数提供理论依据。方法:建立了包含圆柱状V形螺纹种植体的颌骨骨块三维有限元模型,设定螺纹齿高(H)范围为0.2～0.6mm,螺纹宽度(W)范围为0.1～0.4mm。在修复体正中分别进行垂直向100N和45°颊舌向50N的力学加载。观察H和W变化对颌骨平均主应力(EQV)峰值的影响,同时进行变量对颌骨的敏感度分析。结果:在垂直向加载中皮质骨和松质骨的EQV应力峰值增幅分别为4.3%和63.0%;在颊舌向加载中皮质骨和松质骨的增幅分别为19.3%和118%;在各种加载情况下,当变量H位于0.34～0.50mm,同时变量W位于0.18～0.30mm之间时,对颌骨的EQV应力峰值响应曲线的切线斜率位于-1～1之间;变量H比W对颌骨的EQV应力峰值的影响更明显。结论:松质骨的应力大小更易受到螺纹的影响;螺纹对侧向力加载时的力学传递影响更明显;生物力学方面的考虑,圆柱状螺纹种植体最佳的螺纹设计为螺纹高度介于0.34～0.50mm之间,螺纹宽度介于0.18～0.30mm之间;在圆柱状螺纹种植体设计中,相对于螺纹宽度而言应更重视螺纹高度的设计。
AIM： To evaluate the effect of continuous and simultaneous variations of the thread height and width of an experimental cylinder implant on bone stress. METHODS ： Finite element model with a V - shaped thread implant was created. The range of thread height （H） was set from 0.2mm to 0.6mm, and that of thread width （W） from 0.1 mm to 0.4 mm. And forces of 100 and 50N were applied along axis of implant （AX） and an angle of 45° to buccolingual direction （45° BL） respectively. The maximum Van Mises stresses in jaw bone were evaluated, and the sensitivity of the stress in jaw bone to the variables was also evaluated. RESULTS： Under AX load, the maximum Von Mises stresses in cortical and cancellous bones increased by 4.3% and 63.0% respectively according to the change of thread parameter. And under 45°BL load, those increased by 19.3% and 118% respectively. When H was from 0. 34mm to 0.50mm and W was from 0.18mm to 0.30mm, the tangent slope rate of the maximum Von Mises stress response curve ranged from - 1 to 1. And the variation of the maximum Von Mises stresses in jaw bone was more sensitive to H than to W. CONCLUSION： The two thread designs favor stresses in cancellous bone than in cortical bone; and 45°buccolingual force is apt to be influenced by thread design. When the thread height is from 0.34mm to 0.50mm and the thread width is from 0.18mm to 0.30mm, the Max EQV stress in jaw bones reaches the minimal value and the optimal design of thread parameters should be selected from these range by biomechanical consideration. And in a cylinder screwed implant design, the thread height is more important than thread width in reducing bone stress.
出处
《牙体牙髓牙周病学杂志》
CAS
2008年第1期15-19,共5页
Chinese Journal of Conservative Dentistry
