The induction of micronuclei in vitro by unpolymerized resin monomers.

Components of resin materials may damage DNA, leading to genetic alterations in mammalian cells. Here, monomers were analyzed for the induction of chromosomal aberrations indicated by micronuclei induced in V79 cells. A dose-related increase in the numbers of micronuclei was observed with triethyleneglycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and glycidyl methacrylate (GMA). These effects were reduced, however, by a metabolically active microsomal fraction from rat liver. The very low activity of Bis-GMA and UDMA and the elevated numbers of micronuclei caused by high concentrations of methyl methacrylate and bisphenol A were associated with cytotoxicity. Our findings provide evidence for the induction of micronuclei by TEGDMA, HEMA, and GMA under physiological conditions, indicating clastogenic activity of these chemicals in vitro. Since it has been shown that TEGDMA also caused gene mutations and DNA sequence deletions in mammalian cells, the activity of this substance should be analyzed in vivo.