G Uzun1, N Hersek, T Tinçer. 1. Faculty of Dentistry, Hacettepe University, Middle East Technical University, Ankara, Turkey.
Abstract
STATEMENT OF PROBLEM: Fracture strength of denture base resins is of great concern, and many approaches have been used to strengthen acrylic resin dentures. PURPOSE: This study measured the effect of 5 fiber strengtheners on the fracture resistance of denture base acrylic resin material. Impact strength, transverse strength, deflection, and elasticity modulus values of a heat-polymerized denture base resin (Trevalon), reinforced with glass, carbon, thin Kevlar, thick Kevlar, and polyethylene fibers in woven form were studied. MATERIAL AND METHODS: One hundred acrylic resin test specimens reinforced with woven fibers were fabricated. The control group consisted of 20 specimens with no fiber reinforcement. For the impact strength test, a Charpy-type impact tester was used. Transverse strength was assessed with a 3-point bending test by using a screw-driven mechanical testing machine. Ten specimens were used for each test. RESULTS: The highest impact test values were produced by polyethylene-reinforced group, and the lowest values were obtained from specimens containing no fibers. There were significant differences among the test groups, but no significant differences in transverse strength were found. The lowest transverse strength values were obtained for specimens strengthened with polyethylene fibers, which also insignificantly decreased transverse strength of the acrylic resin. CONCLUSION: The impact strength of denture base acrylic resins was increased with fibers in woven form. Tested fibers did not have a significant effect on the transverse strengths.
STATEMENT OF PROBLEM: Fracture strength of denture base resins is of great concern, and many approaches have been used to strengthen acrylic resin dentures. PURPOSE: This study measured the effect of 5 fiber strengtheners on the fracture resistance of denture base acrylic resin material. Impact strength, transverse strength, deflection, and elasticity modulus values of a heat-polymerized denture base resin (Trevalon), reinforced with glass, carbon, thin Kevlar, thick Kevlar, and polyethylene fibers in woven form were studied. MATERIAL AND METHODS: One hundred acrylic resin test specimens reinforced with woven fibers were fabricated. The control group consisted of 20 specimens with no fiber reinforcement. For the impact strength test, a Charpy-type impact tester was used. Transverse strength was assessed with a 3-point bending test by using a screw-driven mechanical testing machine. Ten specimens were used for each test. RESULTS: The highest impact test values were produced by polyethylene-reinforced group, and the lowest values were obtained from specimens containing no fibers. There were significant differences among the test groups, but no significant differences in transverse strength were found. The lowest transverse strength values were obtained for specimens strengthened with polyethylene fibers, which also insignificantly decreased transverse strength of the acrylic resin. CONCLUSION: The impact strength of denture base acrylic resins was increased with fibers in woven form. Tested fibers did not have a significant effect on the transverse strengths.