Effect of the mechanical loading about the flexural strength of acrylic resins reinforced with glass fibers

Abstract

The aim of this research was to analyze the effect of glass fibers incorporation, used in the nautical and aquatic reinforcement, in the flexural strength and mechanical loading of the acrylic resin. Sixty four specimens were made from Dencor™ acrylic resin, divided into four groups: G1 - without fibers and without mechanical loading (control); G2 - without fibers and with mechanical loading; G3 - with fibers and without mechanical loading and G4 - with fibers and with mechanical loading. The resin was manipulated in agreement with the manufacturer and positioned in a metallic matrix (64 x 10 x 3.3 mm); in groups G3 and G4, 0.250 g of fibers were chopped and added to the resin mass. The specimens were stored in distilled water at 37 ºC for 48 hours and submitted to flexural strength test at MTS 810™ machine; the groups G2 and G4 were submitted to mechanical loading (10,000 uninterrupted cycles, 5 Hz and 80 N), and the groups G1 and G3 received load of 1 KN at 5 mm/min. The data were organized in Excel 2000 and submitted to a variance analysis in the GMC 2002 program. The values, in MPa, for the groups 1 to 4 were, respectively: 45.10 + 3.89; 46.04 + 6.01; 54.33 + 5.69 and 50.76 + 9.39. Statistics differences between the groups with and without fibers were obtained and the p value found was p = 0,0002. It was concluded that the incorporation of glass fibers in the acrylic resin increased the flexural strength independently of the mechanical loading. Key words: polymers, glass, dental materials.