Three-dimensional FEM Analysis of Implant for Controlling Stress Concentration on Surrounding Bone.

Abstract

In order to investigate the mechanical effects of the design of osseointegrated dental implant on the surrounding bone, the present study adopted more realistic approach by 3D FEM for stress analysis. An osseointegrated, screw type implant for molar region was selected, and the standard model and modified models in which the cusp inclination was increased to 40°, the abutment inclination was increased to 20° or the occlusal plane was buccolingually expanded were constructed. The results showed that the alteration of the configuration of superstructure, the occlusal contact positions or the occlusal relief variously changed the aspects of the stress distribution. However, any arrangement of these factors could not drastically relieve the stress concentration at the marginal crest of interfacial cortical bone so long as the occlusal contacts were limited to two points. An additional contact on the distal fossa to form three-point occlusal contacts could significantly reduce the maximum principal stresses and relieve the stress concentration.It was reconfirmed through the 3D FEM analyses that the proper design of superstructure, occlusal contour and balanced disposition of occlusal contacts would minimize the stress concentration on surrounding bone in centric occlusion, lateral sliding or mastication of foods and contribute to the good performance of implant restorations.