Stress Induced by Mandibular Screw Retained Hybrid Denture on “All-On-Four” Implant Distribution: Comparison between Three Different Hybrid Denture Materials: In-Vitro Study

Abstract

This in-vitro stress analysis study was conducted on computer generated 3D models supporting mandibular fixed detachable prosthesis to evaluate and compare stresses induced in the implants using strain gauge technology. According to the material used for construction of the fixed detachable prosthesis they were classified into: • Model I: Fixed detachable overdenture made from acrylic resin (poly methyl methacrylate) reinforced by casted metallic framework (cobalt chromium alloy) attached to the implants by screw- retained abutments. • Model II: Fixed detachable overdenture made from high performance polymer (BIOHPP) attached to the implants by screw- retained abutments. • Model III: Fixed detachable overdenture made from acrylic resin (poly methyl methacrylate) attached to the implants by screw- retained abutments. An educational stone model was scanned via 3Shape desktop scanner (3Shape dental Denmark). Then an STL file was generated. In this STL file four implant beds were designed and grooves were designed at the distal aspect of the posterior implants, grooves were also designed at the lingual aspect of the anterior implants to receive the strain gauges. A key index with 2 mm thickness and 2 mm offset with tissue stops was designed for the purpose of creating a space for the mucosa simulator representing the future