Numerical investigation of span lengths affecting mechanical responses in anterior resin-bonded fixed partial denture

The geometric shape and mechanical structure of RBFPD compared to conventional FPD are relatively complex and unstable. The low retention rate between the retainer and abutment affects the prosthesis/abutment interface de-bonding, and closely relates to the design of the prosthesis and varied occlusion status. This study used reverse engineering (RE) and computer-assisted design (CAD) to construct two solid models of anterior RBFPD with different span lengths. After mesh generation, biomechanical interactions of span length in RB prosthesis with two loading conditions (axial and lateral) were performed by FE analysis. The simulated results indicated that lateral occlusal force increased significantly 2-3 times maximum stress than that of axial occlusal force. For different span lengths simulation, the analysis on static movement finds that longer pontic would lead to high stress to the prosthesis. Thus, the length of the pontic has significant effect on the overall intensity of the prosthesis under static clenching loading, and the effect of lateral loading exceeds that of axial loading.