Abstract
Purpose: In recent years, the prosthetic clinical application of the non-clasp denture (NCD) has commonly expanded. However, the mechanical effects of the NCD on the living body during function have been unclear. In this study, we measured the load exerted on the abutment teeth and the residual ridge under the denture base when the NCD was functioning, and we aimed to examine the characteristics of these loads.
Methods: The intermediated missing teeth model was developed to assume the mandibular second premolar and the first molar which were missing. The piezo-electric transducers for load measurement were contained in the abutment teeth, the first premolar and the second molar. The tactile sensor sheet was set on the residual ridge area of the model. Four kinds of experimental partial dentures for each were made of polyamide-nylon resin (PA-NCD), polycarbonate resin (PC-NCD), polycarbonate resin with a metal frame (mPC-NCD), and common acrylic resin (PMMA-CD). These were all examined. Static loads that were increased in stages (10, 30, 50, and 100 N) were applied to the artificial teeth area of the experimental dentures. The loads exerted on the abutment teeth and the load exerted on the residual ridge were examined by comparing these loads among the experimental dentures.
Results: The axial component of the load exerted on the abutment teeth with PMMA-CD was larger than that with PA-NCD and PC-NCD when the amounts of 50 and 100 N loads were applied. The load exerted on the residual ridge with PA-NCD was larger than that with mPC-NCD and PMMA-CD when the amounts of 50 and 100 N loads were applied.
Conclusions: The load exerted on the residual ridge with NCD has been shown to be potentially more excessive than that with the conventional removable partial denture.
