EVALUATION OF IMPACT STRENGTH OF HEAT CURE ACRYLIC RESIN REINFORCED WITH NYLON FIBER MESH WITH AND WITHOUT PRESTRESSING (IN VITRO STUDY)

Abstract

INTRODUCTION: Acrylic resin prostheses are liable to high levels of forces due to their frequent removal by patients and accidental slippage. Hence, the impact strength of acrylic denture base material is of major significance in providing long-term functional prostheses.OBJECTIVES: The aim of this study was to evaluate the reinforcing effect of prestressed nylon fiber meshwork and the specimen thickness increase on the impact strength of heat cure acrylic resin.MATERIALS AND METHODS: 72 specimens were divided into 3 groups (I, II and III) which were heat cure acrylic resin (control), Nylon mesh reinforced acrylic resin and prestressed-nylon mesh reinforced acrylic resin. Each group was formed of 24 specimens, which were further subdivided into 3 subgroups (A, B and C) of different dimensions; 75 mm × 10 mm × 3 mm and 75 × 10 × 4 mm and 75 x 10 x 5 mm. Thus, the specimens were divided into 9 experimental subgroups (n=8 per subgroup). A Charpy’s impact tester was used to measure the impact strength of acrylic resin. The data were analyzed using Anova-test (p≤0.05).RESULTS: The mean impact strength of groups II and III was higher than the control group I impact strength. The difference between the reinforced groups and control group was statistically significant for all specimen thicknesses.CONCLUSIONS: The impact strength of heat cure acrylic resin was increased by the incorporation of nylon fiber mesh whether prestressed or not.