Fracture Strength of Acrylic Resin Reinforced with Glass Fibers in Simulated Implant-Supported Overdenture Abutments

Objective: To evaluate the effect of glass fibers on acrylic resin fracture strength in simulated implant-supported overdenture (IOD) abutments. Methods: A model was designed to simulate the clinical situation of an IDO (50 12 1.5 mm). Thirty models were divided into three equal groups: ten models not supported with glass fibers (control group), ten models with one layer of glass fibers (experimental group I) and ten models with two layers of glass fiber (experimental group II). All models were exposed to a three-point bending test, and fracture loads were analyzed using a one-way analysis of variance (ANOVA) followed by Bonferroni post-hoc test. Results: IOD models reinforced with two layers of glass fibers (experimental group II) showed a mean ultimate load at fracture of 48.69 ± 3.71 Newton (N) compared to mean loads of 32.78 ± 2.41 N and 24.42 ± 2.73 N for the models reinforced with one layer (experimental group I) and non-reinforced with glass fibers (control group), respectively. ANOVA showed a statistically significant difference between the three groups regarding the mean ultimate load at fracture, and Bonferroni post-hoc test showed statistically significant differences between both experimental groups and the control group as well as between experimental group I and experimental group II. Conclusions: The fracture strength of IDO abutments increases significantly by the addition of acrylic resin pre-impregnated with glass fibers, even when the thickness of acrylic is thin.