Strength and cytotoxicity in glass‐fiber‐reinforced denture base resin with changes in the monomer

Abstract

AbstractGlass fibers (GFs) are often used to strengthen denture base resins. An increase in the GF content can result in severe viscosity, bunching of the GFs, and difficulty in the handling and packing of the poly(methyl methacrylate) (PMMA) resin. To ensure better impregnation of the GFs and improvements in the workability, more methyl methacrylate is needed as the percentage of GFs is increased. The purpose of this study was to determine adequate powder/liquid ratios according to the GF ratios to reinforce with GFs and to evaluate the effect of probable residual monomer on the cytotoxicity and mechanical properties of PMMA denture base resin reinforced with different ratios of GFs. Five specimens were made according to the defined powder/liquid ratios. Ten specimens for each group were prepared with a stainless steel mold. The flexural strength (FS) and elastic modulus were measured with a three‐point bending test in a universal testing machine. To examine changes in toxicity with time, three types of specimens for each group were fabricated and immersed for 0, 24, and 72 h in distilled water after polymerization. The cytotoxicity was evaluated with an agar overlay test. The workability was improved, and the FS and elastic modulus of the denture base resin reinforced with GFs were made significantly higher with increases in the amount of monomer. There was no difference between the control group and the GF‐reinforced groups with regard to the cytotoxicity, despite the increasing monomer concentration. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012