Release of residual methyl methacrylate into water from glass fibre-poly(methyl methacrylate) composite used in dentures.

The aim of this study was to determine the release of residual methyl methacrylate (MMA) into water from heat-cured and chemical-cured test specimens of continuous glass fibre-poly(methyl methacrylate) (PMMA) composite fabricated from experimental glass fibre reinforcement. The glass fibre concentration of the test specimens was 12% by weight. The residual MMA was extracted from the storage water of the test specimens (n = 5 per group) and its concentration was determined by high-performance liquid chromatography. The results revealed that release of residual MMA from heat-cured test specimens with glass fibre reinforcement was significantly higher than that from unreinforced test specimens (P = 0.003), while in chemical-cured test specimens with and without glass fibre reinforcement the amount of MMA released did not differ (P = 0.501). In general, however the test specimens made from chemical-cured PMMA released more residual MMA than specimens made from heat-cured PMMA (P < 0.001). This study suggests that the use of glass fibre reinforcement in heat-cured denture PMMA statistically increases the release of residual MMA from the material, but it is questionable whether it has clinical significance.