Synthesis and Characterization of a New Trimethacrylate Monomer with Low Polymerization Shrinkage and Its Application in Dental Restoration Materials

In this study, a new trimethacrylate monomer alpha, alpha, alpha'-tri[4-(2'-hydroxy-3'-methacryloyloxy-propoxy) phenyl]-1-ethyl-4-isopropylbenzene (alpha, alpha, alpha'-THMPEIB) with a molecular weight of 850 and a large molecular volume was designed and synthesized. The structure of monomer alpha, alpha, alpha'-THMPEIB was confirmed by FT-IR, H-1 NMR, and elemental analysis. Degree of double-bond conversion, volume shrinkage, water sorption and solubility, diffusion coefficient value, and flexure strength of alpha, alpha, alpha'-THMPEIB/tri(ethylene glycol) dimethacrylate- (TEGDMA) based resin were measured. 2,2-Bis[4-(2'-hydroxy-3'-methacry-loyloxy-propoxy)-phenyl]-propane (bis-GMA)/TEGDMA monomer mixture was used as reference. The result showed that the alpha, alpha, alpha'-THMPEIB/TEGDMA-based resin had the lower double-bond conversion, polymerization shrinkage, and water solubility than bis-GMA/TEGDMA-based resin. Water sorption and diffusion coefficient value of alpha, alpha, alpha'-THMPEIB/TEGDMA-based resin were nearly the same as those of bis-GMA/TEGDMA-based resin. Flexural strength of alpha, alpha, alpha'-THMPEIB/TEGDMA-based resin was higher than that of bis-GMA/TEGDMA-based resin.