基牙数目对游离端附着体义齿支持组织应力分布的影响

Influence of various abutment number on stress distribution in the attachment denture supporting tissue

目的探讨不同基牙数目下,下颌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,分析在垂直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。结果末端基牙牙周膜应力集中区位于远中的牙颈部,牙槽嵴的高应力区主要位于牙槽嵴顶的近远中两侧。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,应力分布趋于均匀。当基牙数目从1颗增加到2颗时到再增加到3颗时,牙周膜的最大应力约呈等梯度下降,而基牙牙槽骨和牙槽嵴的下降量则明显减少。结论在下颌游离缺损修复中,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。

Objective To investigate the stress distribution in the attachment denture supporting tissue with various abutment number. Methods Reconstructed three-dimensional finite element models of the extra-coronal attachment denture with mandibular Kennedy I dentition defect was established andanalyzed the stress distribution of the denture supporting tissue with yon Mises ability of sustain pressure when vertical forces were applied. Results The max Von Mises stress of the distant-abutments periodontal membrane were found at the distant-cervical and that of the alveolar bone under the denture were found at the mesial and distal alveolar crest. While the abutment number was increased from one to two and to three, the pressure of the distant-abutments periodontal membrane tends to be proportionately decreased; but the pressure of the alveolar bone decreased no-proportionately. Conclusion The pressure decreased in supporting tissue was not in proportion to the numbers increased in abutment for repairing mandibular distal-extension edentulous dentition with extra-coronal attachment.