下颌单个余牙义齿支持组织的有限元分析——全牙列正中加载的应力研究

Finite Element Analysis of Mandibular Supporting Tissues Beneath A Partially Denture with One Remaining Tooth——Stress Analysis of Central Occlusal Loads in Complete Row of Teeth

本文应用三维有限元法对下颌半个余留牙的不同支托设计(包括无支托、远中支托、近中支托和近远中支托)的模型进行垂直载荷条件的应力分析研究。分析在同一加载条件下,上述4种设计的牙槽骨表面和基牙牙周膜的应力分布情况。结果正中(牙合)力作用下,牙槽骨的绝大部分区域为压应力,较大压应力集中在前牙区和前磨牙区的牙槽嵴。加载于无支托义齿时,牙槽骨较大压力区的应力位高于有支托义齿,基牙牙周膜的应力值低于有支托义齿。有支托义齿加载时,牙槽嵴、基牙牙周膜应力值以近远中支托义齿小,且分布均匀。

In order to gain a clear idea of loads transfering to the abutment,alveolar ridgeand mucosa in this study,analysis was made of the magnitude,direction and distribu-tion of the stresses to support tissues for a mandibular case having one tooth left,under different dentural states and with the three dimensional finite element method.The aim was to explore and find out relation of stress distribution pattern amongdifferent states of denture designs,alveolar bone and abutment teeth.The resultsshowed that the stresses on alveolar bone were mainly concentrated on the regions ofthe alveolar ridge between the left and the right first molar.The main stress level ofalveolar ridge was fairly small in the denture with mesial-distal rest,while that ofabutment was comparatively small in no rest.To decrease the stress concentration andto increase the denture stability and retention,we want to preserve many remaining teeth as many as possible and amply extend the denture base,and the artificial teethshould be rearranged to the lingual side along with the progress of the alveolar boneresorption and should be attained the balanced occlusion as far as possible.If the condi-tion of abutment is fairly good,the mesial-distal rest may be set up.