Evaluation of stress distribution of tantalum porous implant and titanium solid implant assisted overdentures in mandibular bone: A three-dimensional-finite element analysis.

Abstract

Purpose: The present study aimed to evaluate the stress distribution of tantalum porous implant and titanium solid IAO in mandibular bone by utilizing three-dimensional finite element analysis. Materials and Methods: An existing cone-beam volumetric tomography (CBVT) scan of a patient without any maxillofacial anomaly and average craniofacial proportions with an available acceptable Implant assisted overdenture for mandible was used to attain the compartments of a completely edentulous mandible. Zimmer trabecular implants and Locator attachment systems were selected as the case group (model B), and Zimmer Screw-vent implants and locator attachment system were chosen for the control (model A), as overdenture attachments in the present study. The mandibular overdenture was scanned and digitized as a finite element model. Two three-dimensional finite element models were designed as edentulous lower jaws, each with four implants in the anterior section of the mandible. Three forms of loads were directed to the IAO in each model: 1. 100 N vertical loads on the left first molar (VM). 2.100 N vertical loads on the lower incisors (VI). 3.100 N, 45° inclined force buccolingually applied at the center of the left first molar (IM). Results: Under all loading conditions the maximum strain values in peri-implant bone in model A were less than model B. Under VI, the greatest stress value around abutments in both models was about 2-3 times higher than the other loads. Under VM and IM loads, no significant difference was observed between models but the pressure on the mucosa was higher in model B under VI load. Conclusion: Using trabecular metal implant instead of solid implants reduces strain values around the both cortical and trabecular bone.