Assumptions in the Use of Fea in the Implant-bone Biomechanical System

THE JOURNAL OF PROSTHETIC DENTISTRY 585 In the past 2 decades, finite element analysis (FEA) has become an increasingly useful tool for the prediction of the effects of stress on the implant and its surrounding bone. Vertical and transverse loads from mastication induce axial forces and bending moments and result in stress gradients in the implant as well as in the bone. A key factor for the success or failure of a dental implant is the manner in which stresses are transferred to the surrounding bone. Load transfer from implants to surrounding bone depends on the type of loading, the bone–implant interface, the length and diameter of the implants, the shape and characteristics of the implant surface, the prosthesis type, and the quantity and quality of the surrounding bone. FEA allows researchers to predict stress distribution in the contact area of the implants with cortical bone and around the apex of the implants in trabecular bone. Although the precise mechanisms are not fully understood, it is clear that there is an adaptive remodelling response of the surrounding bone to this stress. Implant features causing excessive high or low stresses may contribute to pathologic bone resorption or bone atrophy. This article reviews the current status of the application of FEA in implant dentistry. Assumptions made in the use of FEA in implant dentistry are described, and findings from FEA studies are discussed in relation to the bone–implant interface, the implant–prosthesis connection, and multiple-implant prostheses. ASSUMPTIONS IN THE USE OF FEA IN THE IMPLANT-BONE BIOMECHANICAL SYSTEM