中国实用口腔科杂志

中国实用口腔科杂志

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斜向载荷下下颌KennedyⅠ类缺失冠外附着体义齿支持组织应力分析

牟雁东1，樊瑜波2，3，刘 展3   

  1. 1.四川省人民医院口腔科，成都 610071;2.北京航空航天大学生物工程系，北京 100083;3.四川大学生物力学工程实验室，成都 610065

  • 收稿日期:2009-08-10 修回日期:2009-09-15 出版日期:2009-10-15 发布日期:2009-10-15

  • Received:2009-08-10 Revised:2009-09-15 Online:2009-10-15 Published:2009-10-15

摘要：

摘要：目的 探讨斜向载荷下采用不同基牙数目时下颌后牙双侧游离缺损冠外附着体义齿支持组织的应力分布情况。方法 2005年选取一成年健康男性志愿者的头部CT（取下颌牙槽骨部分）和离体尖牙、第一双尖牙、第二双尖牙、第一磨牙、第二磨牙的CT扫描图片。建立下颌KennedyⅠ类牙列缺损冠外附着体义齿修复的三维有限元模型，分析在斜向载荷作用下采用不同基牙数目时，基牙牙周组织及缺牙区牙槽嵴的Von Mises应力分布。结果 斜向载荷下，末端基牙牙周膜应力集中区主要位于颊舌侧的牙颈部，随着基牙数目的增加，基牙牙周组织及缺牙区牙嵴的最大应力值都呈下降趋势，基牙由1颗增加至2颗时，应力明显下降，当基牙增加至3颗时，应力的下降量明显减少。结论 在下颌游离缺损修复中，斜向载荷下冠外附着体义齿支持组织应力的减少与基牙数目的增加不完全成比例，在临床上应根据具体的情况确定联合基牙的数目。

关键词: 三维有限元, 附着体义齿, 斜向载荷, 应力分析

Abstract:

Abstract：Objective To investigate the stress distribution in the bilateral distal-extension attachment denture supporting tissue with oblique forces. Methods Reconstruct the three-dimensional finite element models of the extracoronal attachment denture with various abutment number to mandibular Kennedy Ⅰ dentition defect，analyze the stress distribution of the denture supporting tissue with Von Mises ability of sustain pressure when oblique forces were applied. Results With oblique forces，the max Von Mises stress of the distant-abutments periodontal membrane were found at the buccolingual cervix dentis; while the abutment number was increased，the max pressure of the distant-abutments periodontal membrane and the alveolar bone decreased;while the abutment number was increased from one to two，the pressure obviously decreased，and the number from two to three，the pressure decreased slowlier. Conclusion With oblique forces，the pressure decrease of supporting tissue of extra-coronal attachment is not in proportion to the increase of abutment number.

Key words: 3D finite element, attachment dentures, oblique forces, stress analysis