[Three-dimensional finite element analysis of removable partial denture with periodontally compromised abutments]

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.

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.

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.

3D non-contact digitalizing scanner was useful for the finite element modeling process of removable partial denture.