The evaluation of flexural strength and impact strength of heat-polymerized polymethyl methacrylate denture base resin reinforced with glass and nylon fibers: An in vitro study

Abstract

With the advent of newer denture base materials, fiber reinforcement in polymethyl methacrylate (PMMA) acrylic resin by various fibers to improve the strength properties of PMMA denture base materials is common nowadays. So it has become imperative to evaluate which fiber suits best to improve both flexural and impact strengths of the denture base resin and to know up to what extent the fiber-reinforced PMMA denture base resin fulfills the strength requirement of an ideal denture base material. This study compared the resistance-to-fracture properties of a commercially available heat-polymerizing PMMA denture base resin with those of the same material reinforced by glass and nylon fibers. The fibers were randomly oriented and used in concentration of 2% by weight. The 20 test specimens of similar dimensions were prepared for each of the 4 experimental groups, viz., conventional PMMA denture base resin; and the same resin reinforced with monomer-treated glass fibers, silane-treated glass fibers, and monomer-treated nylon fibers. A total of 10 test specimens from each study group were subjected to three-point bend test on a Universal Instron testing machine, and the remaining 10 test specimens were tested for impact strength by Charpy's pendulum impact strength tester. From the literature, it was found that the flexural and impact strengths of heat-polymerized PMMA denture base resin reinforced with fibers are significantly more than those of the conventional heat-polymerized PMMA denture base resin.