Synthesis, characterization and polymerization characteristics of new dimethacrylates, derived from 3,3,5-trimethylcyclohexan-1-one-phenol adducts, as monomers for dental composites

The object of this study was to synthesize, characterize and evaluate sever al new dimethacrylate monomers, in order to discover new compositions for p ossible formulation of improved dental restoratives, Dimethacrylates derive d from the 3,3,5-trimethylcyclohexan-1-one-phenol reaction products were pr epared and characterized by Fourier transform infrared and nuclear magnetic resonance. Thermal- and photopolymerization characteristics of these exper imental monomers, in blends with triethyl-eneglycol dimethacrylate (TEGDMA) , were evaluated by differential scanning calorimetry and differential phot ocalorimetry. An additional dimethacrylate derived from the 3,3,5-trimethyl cyclohexanone-phenol adduct, supplied by Bayer AG, was also evaluated durin g the study. A control for comparison consisted of a 2,2-bis[4-(2-hydroxy-3 -methacryloyloxy-propyl) phenyl]propane (BisGMA) blend with TEGDMA. It was found that the polymerization behavior and properties of the visible light- cured neat resins were dependent on their chemical structures. The experime ntal resins exhibited comparable curing characteristics, lower water sorpti on, higher wet glass transition temperature, and other improved properties, compared with the polymerized BisGMA/TEGDMA control. The more rigid and hy drophobic nature of the experimental resins, accomplished by incorporation of the bulky trimethyl-substituted cyclohexyl moiety in the novel dimethacr ylates, was considered to be the major factor contributing to the improved properties. These new dimethacrylates, for formulating thermosets with lowe r water sorption and higher glass transition temperature may offer a path t o improving composites for a variety of applications, including such things as dental restoratives and bone cements. Copyright (C) 1999 John Wiley & S ons, Ltd.