不同牙周夹板固定下颌前牙的有限元模型建立及牙周膜应力分布的有限元分析

A finite element study of the periodontal ligament stress distribution of mandibular anterior teeth fixed with different periodontal splints

目的:评价两种不同牙周夹板固定对牙周膜内等效应力的分散以及牙周固定后患牙位移情况。方法:选用1名牙周健康志愿者的CBCT资料,通过计算机图像处理系统及有限元软件建立41牙不同松动度的有限元模型,对实验牙进行25 N力学加载,斜向舌侧分别与牙轴呈0°、15°和25°。研究不同松动度的患牙经牙周夹板固定后应力分布的变化和患牙的位移量。结果:随着松动度的增加,41牙周膜内最大应力较不松动时增加122%~1035%,斜向加载时更为明显;在牙周夹板固定后应力减小16%~78%,牙齿的位移量也明显减少。结论:牙周夹板固定能分散力,降低牙周膜内应力集中,Super-Bond C&B效果优于FRC,应力分散效果更为明显。

Objective:To analyze the stress distribution of mandibular anterior teeth fixed by different splints.Methods:Normal mandibular anterior teeth of a healthy volunteer was scanned by CBCT,the images were transfered into DICOM file and then put into Mimics finite element software,the finite element model of 41 was established,the stress distribution of the anterior teeth with various degrees of mobility and fixed by Super-Bond C&B and fiber reinforced composit(FRC)splint respectively was analyzed.Results:With the increase of the mobility from degree I to III,the maximum stress in the periodontal ligament was increased by 122%-1035%compared with that of the healthy control,and the stress peak increased more obliquely during the oblique loading.A load of 25 N was loaded on the incisal margin of 41 at 0°,15°and 25°respectively to the tooth axis lingualy,the periodontal splint fixation reduced the stress by 16%-78%,the displacement of the tooth was also reduced,4META showed stronger effects than FRC.Conclusion:The periodontal splint fixation can disperse the occlusal force and reduce the stress concentration in the periodontal ligment,Super-Bond C&B is more effective than FRC.