Stress distribution in a mandibular implant-supported prosthesis with implant bridge manufacturing in CAD/CAM and by conventional techinique: photoelastic stress and strain-gauge analysis

Abstract

The aim this study is to assess the stress distribution in the bone-implant interface through photoelastic and strain-gauges analysis of a mandibular implant-supported prosthesis with implant bridges made with different materials and techniques of manufacturing under compressive force. A photoelastic model of an edentulous mandible, containing five external hexagon implants (4 mm × 13 mm each) will be constructed. Experimental models will be divided into three groups: Group 1 - implant bridge fuse in Nickel chrome and acrylic resin coating; Group 2 - implant bridge fuse in nickel chrome and porcelain coating; Group 3 - CAD/CAM zirconia implant bridge and porcelain coating. Firstly, photoelastic stress analysis will be made and afterward the strain-gauges analysis. Forces of 100 N will be applied in incisor region and the center of the first molar on each side. The resulting stress distributions will be analyzed through photographic images and Adobe Photoshop CS6 software according to the number of high intensity fringes as also the area of stress distribution. For the strain-gauge analysis, measuring will be performed in two different regions. For the first region two strain gauges are positioned horizontally on the mesial and distal region of the five implants directly on the marginal ridge of the photoelastic model. For the second region, the photoelastic resin will be removed from the mesial and distal surface of each implant leaving 1 mm of intact resin, which will be fixed vertically the strain-gauges. The same compression tests described above will be realized. The electrical signals are captured by a data acquisition device controlled by a computer and were processed by specific software. The mean values recorded will be grouped in tables and subjected to statistical analysis. (AU)