Mechanics Comparison of Various Designs of Implant-supported Mandibular Restoration

Abstract

The purpose of this study was to compare the effects of various designs of implants' placement on stress distribution in bone around the implants supporting one-unit fixed complete dentures. A computer tomography image was redrawn to reconstruct a digital three-dimensional solid model of a mandible including the cortical bone and cancellous bone. Moreover, the reverse engineering method and computer-aided design were employed to construct a digital three-dimensional solid model of fixed complete dentures as well as implant and abutment. All of the digital three-dimensional solid models were combined and transformed to the FE models, and they were classified into 7 configurations according to the number and location of the implants. The MSC/Patran software was used to develop the FE mesh comprising of 1101954 elements with 252693 nodes. The MSC/Nastran software was utilized as pre and post-processor for all mathematical calculations necessary to evaluate dental and mandibular biomechanics. One set of multiple vertical loads was used to simulate the possibility of occlusion status. And the von Mises stress values in the cortical bone, cancellous bone and implants were evaluated. The simulated results indicated that the stress distributions for FE models were largely affected by the number and location of implants. In the bone, similar to the single-tooth case, the von Mises stresses were all concentrated toward the cortical bone around the collar of the implants for FE models. By increasing the thickness of each connector of complete dentures, the stress distribution for cortical bone around implants could be decreased.

Keywords

• implant-supported
• reverse engineering
• computer-aided design
• finite element analysis
• computer tomography
• fixed complete dentures
• von mises stress
• cortical bone
• cancellous bone
• mandibular restoration