Abstract
Three kinds of commercially available composite resins were used.On a slice of cattle anterior tooth was placed a plastic ring (inner diameter 5mm, height 2mm), which was then filled with one of the composite resins. After 1 and 7 days, the plastic ring was removed, and amount of methacrylate monomer in the slice and the hardened resin block was determined by high performance liquid chromatography. The residual amount of monomer in the hardened block increased with the monomer content in the unhardened resin. In repeated experiments with the same resin, amount of Bis-GMA was positive correlated with the amount of Tri-EDMA in the same specimen. However, the amounts of the monomers migrating to the specimen were not correlated with the residual amounts of the monomers in the hardened block. In addition, The migration of Bis-GMA to dentin increased with time, whereas no increase of Tri-EDMA was observed.
