下颌固定义齿桥基牙数目对支持骨组织应力的影响

Three-dimensional finite element analysis of effects of the number of abutment teeth on stress of alveolar bone

目的探讨多基牙固定义齿在牙周组织受损条件下,桥基牙数目与支持骨组织内应力变化的关系。方法采用三维有限元方法,通过改变基牙数目与牙槽骨的支持高度建立有限元模型进行计算分析。结果牙槽骨高度降低的条件下,基牙牙槽骨组织应力值增大;固定义齿修复后,支持骨组织应力值下降;随着基牙数目的增多,支持骨组织应力值降低,但与基牙数目的增多不成比例;与垂直向载荷相比,斜向载荷易导致支持组织应力集中,应力分布规律有明显的改变。结论下颌后牙固定桥的应力分布与基牙数量在一定程度内具有相关性。

Objective To study the stress distribution of rigid fixed bridge on the number of abutment teeth of periodontal membranes around abutments. Methods Three-dimensional digital model of fixed denture on mandible posterior teeth was developed. Stress distribution of fixed bridge loaded with the vertical and horizontal forces was analyzed during the changes in the number of abutment teeth. Results When the height of periodontal support was reduced the distribution trends of the stresses in the fixed denture and periodontal support of abutments were similar. The compress in the periodontal support and alveolar bone was concentrated in the tip of the abutment roots when fixed denture was loaded vertically. The direction of the load could influence the stress distribution on the periodontal support interface and the lateral occlusion force was harmful to the abutment and structure of fixed denture Conclusion There is a relationship between the stress distribution fixed bridge on mandible posterior teeth and the number of abutments teeth.