Residual monomers (TEGDMA and Bis-GMA) of a set visible-light-cured dental composite resin when immersed in water.

Rods of a visible-light-cured dental composite resin were photo-polymerized and immersed in water at 37 degrees C for 7 days. The residual monomers (TEGDMA and Bis-GMA) trapped in the set composite and those eluted into water were analysed by gas-liquid chromatography. It became evident that minor amounts of the residual monomers dissolved in water, but that most residual monomers remained in the set composite. Extension of the irradiation period contributed to the significant reduction in the residual monomer level and its elution into water.