An <i>in vitro</i> study of the effect of design of repair surface on the transverse strength of repaired acrylic resin using autopolymerizing resin

Abstract

Statement of Problem: The fracture of complete denture is a common occurrence in the field of prosthodontics. Often if all other criteria are met such as good aesthetics, occlusion, and functionality; denture repair is acceptable. Once denture fractures, we would want the joint surface strength to be as good as original.
Purpose: The purpose of this study was to determine the effect of different repair surface design on the transverse strength of repaired acrylic denture resin.
Materials and Methods: Sixty specimens of heat‑cured acrylic resin of dimension 65 mm × 20 mm × 2.5 mm were prepared using a special die. Transverse strength of 15 samples was calculated which serves as a control group. Three different types of joint surface contours were prepared each having 15 samples each as butt, round, and rabbet joint. Transverse strength of three joint contours was then compared with control group and also they were compared with each other and result was statistically analyzed with one‑way analysis of variance (ANOVA) and Post‑hoc ANOVA Tukey’s HSD test at 5% level of significance. Z‑test of proportion was also done for types of failures.
Result: Transverse strength of original specimen was higher than that of repaired specimens. Transverse strength of round joint was higher than the butt and rabbet joint.
Conclusion: Methods of repair have significant effect on strength of repaired denture. Round joint design of repair technique was far superior.

Key words: Autopolymerizing resin, rabbet joint, transverse strength