Biomechanical Evaluation of a Fiber-Reinforced Composite Prosthesis Supported by Implants With and Without a Microthread Collar Design

Abstract

Background/purpose: A fiber-reinforced composite (FRC) resin system was introduced as an alternative for implant-retained fixed dental prostheses (FDPs); however, the stress distribution in the bone around the implants which support the FRC-FDP has so far not been reported. The aim of this study was to investigate the biomechanical behavior of FRC-FDPs supported by implants with different collar geometries. Materials and methods: A 3-dimensional finite element analysis method was selected to evaluate the stress distribution. FRC-FDPs were supported by 2 different dental implant systems with 2 distinct collar geometries: a microthread collar structure (MCS) and a non-MCS (NMCS). In separate load cases, 300-N vertical, 150-N oblique, and 60-N horizontal forces were simulated. Tensile and compressive stress values in the cortical and cancellous bone and von Mises stresses in the fixture-abutment complex, the framework, and veneer material were calculated. Results: The MCS model revealed higher compression stresses at the cortical bone than did the NMCS model under all 3 load conditions. Moreover, higher tensile stresses under the oblique loads at the cortical bone were shown with the MCS model. In each model, stresses were much higher in the implant abutment complex than in the cortical bone, and they were very low in the cancellous bone. Conclusion: Although additional experimental and clinical studies are needed, FRC-FDPs can be considered a suitable and alternative treatment choice for an implant-supported prosthesis. The implant design and geometry affect the load-transmission mechanisms. Implants with an MCS that supports FRC-FDPs were shown to be superior in terms of the stress distribution in the bone around the implant compared to implants with an NMCS. Copyright (C) 2010, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved.