POLYMERIZATION CONTRACTION AND CONVERSION OF LIGHT-CURING BISGMA-BASED METHACRYLATE RESINS

The aim of this study was to investigate the polymerization contractio n and the conversion of light-curing methacrylate resins based on bisp henol-A bis(2-hydroxypropyl)methacrylate (BisGMA) diluted with triethy lene glycol dimethyacrylate (TEGDMA), methyl methacrylate (MMA), hydro xypropyl methacrylate (HPMA) or (+/-)-2-ethylhexyl methacrylate (EHMA) . The contraction measurements were carried out with a linometer, a si mple device to determine true linear polymerization contraction of liq uid monomers at ambient temperature. The contraction increased with th e amount of diluting monomer. The estimated conversion of the BisGMA-T EGDMA, calculated using the contraction, is consistent with literature values. The BisGMA-HPMA mixtures showed high conversions at moderate contraction.