Chair:  Masayuki Hideshima (Tokyo Medical and Dental University)

poster discussion


The thickness of the resin base needed to the top of copings 

-Examination by the three-dimensional finite element method-

 M. Obayashi1, T. Ohyama1,2, S. Nakabayashi1,2

S. Tadokoro1, N. Shibuya1, H. Yasuda1, T. Okubo1 and T. Ishigami1,2

 1Department of Partial Denture Prosthodontics, Nihon University School of Dentistry

2Division of Clinical Research, Dental Research Center, Nihon University School of Dentistry



Denture fracture is common complication in overdenture because the thickness of denture base is often not enough above the copings. The thickness of denture base should be enough for the prevention of denture fracture. However the enough thickness of denture base has not been clear. In this study, the correlationship between the thickness of resin and stress concentration above the root cap was assessed using three-dimensional finite element (FE) method. Three-dimensional FE models consisted of plunger , a resin plate and copings for FE method. 3-point bending test and 4-point bending test (cantilever model) were examined using both of FE method and model-testing. The fracture part in model-testing was similar to the part of high  stresses in FE method. An increasing of thickness of resin reduced stress concentration and displacement of resin plate. Those results suggested that the risk of denture fracture is reduced by an increasing of thickness of denture base. Further experiment is warranted to identify the required thickness of denture base.