Substances released from dental resin composites and glass ionomer cements

An increasing number of cavities in the primary and permanent dentition is restored with tooth-colored materials, especially dental resin composites or glass ionomer cements. Several investigations have revealed that various components are segregated from different composite filling materials into an aqueous environment after polymerization. Most organic substances can be extracted from a set resin by organic solvents (methanol, tetrahydrofuran, ethanol). Furthermore, in most studies, the co-monomer TEG-DMA has been identified as the main compound released from polymerized resin composites into aqueous media. However, small quantities of the monomers (Bis-GMA, UDMA) and other co-monomers, as well as additives, may also be released into water. Very little data have been published about substances released from various types of glass ionomer cements (GIC), except the liberation of fluoride. Erosion studies have revealed that there is a considerable disintegration of GICs at lower pH-values. However, the nature of the eroded substances has not yet been clarified. Altogether, the data presented in this review indicate that information is comparably scarce for resin composites and GICs in comparison to the rich amount of knowledge concerning amalgams. Therefore, further studies are necessary to determine quality and quantity of substances segregated from resin composites and GICs.