Purpose: This study evaluated the effect of short glass fibers on the transverse strength of a heat-polymerized acrylic resin denture base material.
Materials and methods: Four groups of specimens (n = 10) were fabricated according to the ISO standard for the transverse strength test. E-glass fibers were triturated to produce short fibers of different lengths. Specimens for Group 1 (control) were made of unfilled polymethylmethacrylate (PMMA). For group 2, the PMMA powder was modified with 0.1 g of dry glass fibers. For group 3, the PMMA powder was modified with 0.1 g of silanized glass fibers. For group 4, the PMMA powder was modified with 0.2 g of silanized glass fibers. A three-point loading test was used to determine the transverse strength of the tested specimens. The fracture surface of each specimen was evaluated using SEM.
Results: The addition of untreated glass fibers increased the transverse strength by 11% but produced some porosity in the polymeric matrix. The addition of silane-treated glass fibers increased the transverse strength of PMMA by 28% for group 3 and by 26% for group 4, and produced a dense structure for the polymer-fiber composite.
Conclusion: The transverse strength of PMMA can be slightly increased by the addition of short glass fibers.