套筒冠与卡环固位型义齿修复末端游离缺失的应力分布比较

Comparison of stress distribution on telescopic denture and clasp-retention denture for bilateral free-ended cases

目的通过模块化方式建立套筒冠及可摘局部义齿的三维有限元模型,比较三种修复体的应力分布特点。方法调用正常牙列模型库编辑建立双侧末端游离缺失的牙列模型,在固定义齿模型库及可摘局部义齿模型库基础上,借助DELL Precision图形工作站,利用UG 5.0、HyperMesh 7.0和Abaqus 6.5软件,建立套筒冠义齿及近中支托和远中支托的可摘局部义齿三维有限元模型,进行有限元力学分析和比较。结果在套筒冠义齿,基牙牙根及牙周膜、牙槽黏膜和牙槽骨的应力分布均匀,其牙根受力最大值(6.205MPa)明显小于其他两种可摘局部义齿设计(分别为18.41MPa和34.49MPa)。结论采用套筒冠设计修复双侧末端游离缺失病例,具有应力分布均匀,基牙受力较小的优点,有利于基牙及周围组织的健康。

Objective To establish three dimensional finite element model libraries of telescopic dentures and removable partial dentures by means of model libraries,and compare the characteristics of stress distribution among three prostheses.Methods Normal model libraries were imported and edited,and models of bilateral free-ended cases were established. Based on the model libraries of fixed partial dentures and removable partial dentures,the finite element models of telescopic dentures and removable partial dentures with medial or distal occlusal rest were established using softwares such as DELL Precision Graphics Workstation,UG 5.0,HyperMesh 7.0 and Abaqus 6.5,then finite element stress analysis was performed. Results The stress distribution on abutment root,parodontium,alveolar mucosa and alveolar bone was uniform. The maximum value of stress on the abutment root （6.205 MPa） was much less than those of two removable partial dentures （18.41 MPa and 34.49 MPa）. Conclusion For bilateral free-ended cases,the telescopic denture design is uniform in stress distribution with less stress on abutment root,which is healthy to the abutment root and surrounding tissues.