When two canine abutment teeth are used to support an overdenture prosthesis, optimal stress distribution to minimize forces to abutments is desired.

This study used photoelastic stress analysis to compare the stress patterns generated around canine abutments using two different overdenture retainer designs.

Two canine abutments were anchored in the photoelastic mandible and overdentures were fabricated using two different overdenture attachments. The fitting surface of dentures were lined with resilient layer of light bodied silicon rubberbase impression material to simulate oral mucosa. The attachments used were Bar-Clip and Short coping type. Verticalload of 5 to 50 lb was applied by jaw simulator. Resultant stress fringes were photographed and evaluated quantitatively.

Bar-Clip type of attachment transmitted more amount of stress than short coping type transmitted. There was gross difference in magnitude of stresses between two types of retainers.

As the retentivity of the attachment increased there was more stress concentration around the abutments.

Dwivedi A, Vyas R, Gupta A. Quantitative Evaluation and Comparison of Stress Transmission Characteristics of Bar-Clip and Short Coping Overdenture Attachments Under Dynamic Loading: A Photoelastic Stress Analysis. J Contemp Dent Pract 2013;14(2):287-292.