Stress distribution analysis in implant-retained palatal obturator prosthesis according to retention system types when subjected to tensile forces: photoelastic and strain-gauge analysis

Abstract

The aim of this study is to evaluate the influence of different retention systems in implant-retained palatal obturator prosthesis at dissipation loads in tensile forces, by the methods of photoelastic and strain-gauge. A photoelastic model of a jaw with buccosinusal communication with three external hexagon implants 4x13mm will be fabricated for tests. Two palatal obturator prosthesis will be fabricated and duplicated which are divided in two groups according to the retention systems (o'ring and bar-clip). The strain-gauge analysis are undertaken separately and after photoelastic stress analysis. Charges are applied by an universal testing machine(EMIC). Three types of displacement are performed (vertical, anterior and posterior) on implant-retained palatal obturator prosthesis, then three metal hooks were attached to the buccal surface of each experimental overdenture in the mid-anterior and bilateral molar regions. For the photoelastic tests the images are recorded and transfered to a computer for qualitative analysis by using image software (Adobe Photoshop CS6). The analysis was divided according to the number of fringes with high intensity (green-pink transtition) and to the stress distribution area. Two strain gauges will be cemented horizontally on the mesial and distal surface of the photoelastic resin model in close proximity of each implant. The strain-gauge signals are digitized by a data acquisition system and displayed in a computer by corresponding software. The recorded tension values means will be grouped in tables and subjected to statistical analysis.