APPLICATION OF DIOL DIMETHACRYLATES IN DENTAL COMPOSITES AND THEIR INFLUENCE ON POLYMERIZATION SHRINKAGE

Diol dimethacrylates (DD) that possess long aliphatic chains were inco rporated into the conventional dental resin mixtures (e.g., BIS-GMA an d TEGDMA) in order to reduce the polymerization stress and shrinkage o f final copolymers. It was found that the polymerization shrinkage of the standard copolymer (60 mol % BIS-GMA and 40 mol % TEGDMA) could be reduced even by 20% when TEGDMA is substituted by a long aliphatic di ol dimethacrylate. These phenomena can be attributed to the low miscib ility of BIS-GMA and DD, which causes long aliphatic chains of DD to r emain in coil form in a reaction mixture. The coils can be unwound and expand as a result of the formation of covalent bonds during polymeri zation and thus reduce the polymerization shrinkage. (C) 1997 John Wil ey & Sons, Inc.