摘要目的 探讨三维红外扫描用于可摘局部义齿三维有限元建模的可行性,并分析基牙牙周损伤对可摘局部义齿应力分布的影响,以期为临床提供参考.方法 利用齿科非接触式红外扫描仪和Simpleware软件对下颌肯尼迪分类法Ⅱ类缺损的可摘局部义齿进行三维建模,构建正常牙槽骨组、牙槽骨吸收组和牙槽骨吸收伴牙周膜增宽组三维有限元模型.使用Abaqus有限元分析软件,研究垂直加载和颊侧45°加载条件下3组牙槽骨的应力分布.结果 垂直加载和颊侧45°加载条件下,3组模型均在义齿近中基牙和剩余牙槽嵴远中出现应力集中；牙槽骨吸收伴牙周膜增宽组近中基牙的应力最大(分别为3.57和2.50 MPa),其次为牙槽骨吸收组(分别为3.21和2.41 MPa),正常牙槽骨组最小(分别为2.63和1.79 MPa).颊侧45°加载时3组模型剩余牙槽嵴远中颊侧和远中位点上的应力值均大于垂直加载.结论 基于三维红外扫描的有限元建模方法是可摘局部义齿有限元应力分析有效的建模方式.

abstractsObjective To evaluate three-dimensional (3D) finite element (FE) modeling of different periodontally compromised unilateral distal extension removable partial denture (RPD) abutments using the data of a 3D non-contact digitizing scanner.Methods FE models were established,and the following structures were simulated in the models:alveolar bone,mucosa,abutments,periodontal ligaments,framework and artificial teeth.The alveolar bone and periodontal ligaments around the distal abutment in the three models were designed as normal,with bone defect and with periodontal ligaments defect respectively.Vertical or buccally inclined forces of 50,100,100 N were applied on the artificial teeth of the RPD and the stress distributions on the supporting tissues were calculated.Results Under vertical loading,the maximal stress on the alveolar bone of the abutment were as follows:periodontal ligaments defect model (3.57 MPa) ＞ bone defect model (3.21 MPa) ＞ normal model (2.63 MPa).Under buccally inclined loading,the maximal stress on the alveolar bone of the abutment were as follows:periodontal ligaments defect model (2.50 MPa) ＞ bone defect model (2.41 MPa) ＞ normal model (1.79 MPa).Under buccally inclined loading,the stresses on distal aspects of the residual alveolar ridge were higher than that of the vertical loading model Conclusions 3D non-contact digitalizing scanner was useful for the finite element modeling process of removable partial denture.