Toxicity of the dental monomer BisGMA using cultured THP-1 cells as a model system.

Abstract

Bisophenol A-diglycidylmethacrylate (BisGMA) is the most frequently used monomer in polymer-based dental composites. Studies have shown that leaching from these materials can occur, and both dental personnel and patients are likely to be exposed to methacrylate monomers. In this study, an in vitro cell culture, THP-1, was employed to investigate cellular effects of BisGMA exposure. The results show that BisGMA will reduce cell viability, and fluorescence microscopy suggests the reduced cell viability is owed to increased cell death (apoptosis and necrosis). Other methacrylates induce toxic effect by binding to the antioxidant glutathione (GSH) and to cause an increase in the generation of reactive oxygen species (ROS). BisGMA exposure did not appear to affect the level of both GSH and ROS. The addition of some antioxidants produced an effect on cell viability, but this effect could not be identified as change in cell death or cell cycle distribution. Other BisGMA exposure studies have observed altered cell growth patterns and DNA damage. This was not verified by the current study, by investigating cell growth or by analysing DNA damage response proteins. Many studies show that other methacrylates will bind to GSH, increase ROS and induce DNA damages. The results from the current study suggest that BisGMA has an alternative mechanism of toxicity compared to other methacrylate monomers.