Abstract
To determine the effects of various dimethacrylate monomers on setting characteristics of composite resins, seven types of UDMA・EDMA based photo cure composite resins were investigated.The base monomer used in this study was a 50/50% mixture in molar ratio of various ethyleneglycol dimethacrylates and urethane dimethacrylate(UDMA).And silicafiller particles(1.9μm), surface treated with a silane coupling agent(3.26% γ-MPTMS), were added to the base monomer in a weight ratio of 65%.The results obtained were as follows.When the repeating structural unit(n)of〓OCH_2CH_2〓_n of ethyleneglycol increased from 1 to 23, Knoop hardness and polymerization shrinkage of the composite resins examined decreased from 62.1 to 6.56 and from 7.831% to 1.478%, respectively.Inversely, unreacted substance increased from 1.21% to 5.51% with increase of n.
