天然上颌中切牙与种植体应力规律的三维有限元分析

背景：生物力学相容性是保证种植体与骨结合后长期稳定并行使功能的必要条件，因此，了解上颌中切牙与其周围骨组织应力应变分布情况对种植义齿修复尤为重要。目的：根据天然牙5种不同解剖分型，探讨上颌中切牙牙根与种植体的应力分布规律。方法：根据天然上颌中切牙5种不同解剖分型，通过UGNX、ANSYS等软件建立种植体及周围局部结构的三维有限元模型(B1、B2、M1、M2、P1)，对种植体施加与牙长轴的夹角成0°、30°、45°、60°、90°的100 N静态荷载力，分析5类上颌中切牙牙根与种植体的应力分布情况。结果与结论：5种分型中，天然中切牙与种植体等效应力随着加载力角度的增大而增大，种植体上升趋势高于天然牙。天然牙等效应力最大值集中在B1，最小值在M1，而种植体等效应力最大值在M1，最小值在M2。天然牙牙根等效应力有2%-31%的差距，种植体等效应力有4%-21%的差距，种植体的应力分布区间小于天然牙牙根的应力分布区间。说明种植体与天然牙随着咬合力角度的增大与受力呈正比，种植体所能承受的咬合力小于天然中切牙。中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程全文链接：

Stress distribution in natural maxillary central incisor and implant: a three-dimensional finite element analysis

BACKGROUND: Biomechanical compatibility is the necessary condition to ensure the stable osseointegration with implants that then can function over a long period; therefore, it is especially important to get knowledge about distribution of stress and strain between the maxillary central incisor and its surrounding bone tissue. OBJECTIVE: Based on five different anatomical types of natural teeth, to study the regularity of stress distribution between the maxillary central incisor root and implant.  METHODS: According to the five different anatomical types of natural maxillary central incisors, UGNX and ANSYS were used to set up three-dimensional finite element models (B1, B2, M1, M2, P1) for the implant and surrounding structures, which were under 100 N static load at angles of 0º, 30º, 45º, 60º, 90º with the long axis of teeth. Then, the stress distribution between the five kinds of maxillary central incisor roots and implants was analyzed. RESULTS AND CONCLUSION: Among the five different anatomical types, the equivalent stress for both the natural central incisor and implant were increased with the increasing of angles, and the implant had a higher raising trend. The equivalent stress for the natural tooth concentrated upon B1 for the maximum value and M1 for the minimum value; while the equivalent stress for the implant focused on the maximum value at M1 and the minimum value at M2. There was a gap of 2%-31% between the equivalent stresses for the natural tooth roots and a gap of 4%-21% for the implants. The stress distribution range for the implant was just smaller than that for the natural tooth roots. It implies that the bit force of implant and natural tooth is in positive proportion to the bite angles, and the bite force that implant can burden is smaller than that the central incisor can.