Evaluation of Stresses Induced by OT Bridge Prosthetic System with Different Number of Scews in All on Six Maxillary Prosthesis (In Vitro Study)

Abstract

The hazardous stresses that could be induced by missing or broken screws in full-arch implant prostheses and the occasional esthetic need for eliminating screws mandate selecting stable prosthetic systems even with a lack of full screw connection. Using finite element analysis this study aims to evaluate the stresses induced by the OT-bridge system (Rhein83®) in the absence of an entire screw anchorage. After exporting the geometry information of; a CAD/CAM prototype of an edentulous maxilla with six implants, and its framework that will be simulated using OT bridge system “extragrade” abutments to the meshing software, boundary and loading conditions will be set and the analysis will be run under axial load 250 N and non- axial load 150 N at 30° inclination. The average Von Mises stress, and displacement values will be calculated for a number of 43 components of five test groups categorized according to the number and distribution of the applied screws. Data obtained from comparing the groups will be used to determine what is the maximum number of screws that could be eliminated without affecting the prosthetic stability or inducing hazardous stresses.