[Stress distribution on periodontium of separated removable partial denture assembly]

The objects of the present study were to construct a computer model and to evaluate the load and stress of denture by means of three dimensional finite element analysis in order to provide evidence for clinic application.

The study utilized CT to scan the maxilla of a healthy man to receive the primal data, and then used Materialise Mimics 9.1 to establish a series of two-definite images artificially and automatically. The three dimensional finite element model of partial maxilla, including teeth, bone and softy tissue, could be constructed in Pro/Engineer WF 2.0 software by using related commands. The separated removable partial denture assembly was finally set up according to the denture design in Pro/Engineer WF 2.0. After converting data into Ansys Workbench 9.0, the command of meshing was fulfilled. Applying different loads on artificial teeth, the data about the stress on the periodontium, abutment and supporting tissue were obtained.

Statistical comparisons showed that the stresses of periodontal membranes had no significant differences, but the periodontium under saddle changed greatly under different loads.

This study shows that the separated removable partial denture assembly can undertake the retention and load respectively due to special design. It is the two layers of bases that can protect the healthy of abutments. This design may be applicable for the restoration of the tooth with poor periodontium around abutments.