Dr. Alok Dwivedi MDS
Faculty of dentistry, Najran University, Kingdom of Saudi Arabia
Title: Photoelastic Evaluation and Comparison of Stress Transmission Characteristics of Three Different Overdenture Attachments Under Dynamic Loading Conditions – An in Vitro Study
Biography
Biography: Dr. Alok Dwivedi MDS
Abstract
Purpose: In this study photoelastic stress analysis was used to compare the stress patterns around canine abutments using three different overdenture attachments.
Material and methods: Two teeth ie canines were used as abutments and were embedded in the photoelastic model made by clear photoelastic plastic resin CY 212(Araldite). Overdentures were fabricated using Ball-Socket, Tissue bar and short coping attachments. The layer of light bodied silicone rubber base impression material was used to simulate oral mucosa and load of 5 to 50 lb was applied. Stress fringes that generated were photographed and evaluated quantitatively.
Jaw Movement Simulator: The machine that was constructed to generate masticatory strokes was named ‘’jaw simulator’’. 150 masticatory strokes per minute were generated. It has an upper jaw in which upper denture was mounted with the cast. There is a centrally located rod in the upper jaw plate to hold the dead weights. The lower jaw plate held the photoelastic model.
Results: The highest amount of stress was generated by Ball-Socket and short coping transmitted least amount of stresses. There was gross difference in magnitude of stresses between two types of retainers.
Conclusion: There was more stress concentration around the abutments as the retentivity of the attachment increased.