title: Effects of molecular structure of the resins on the volumetric shrinkage and the mechanical strength of dental restorative composites.
abstract: To prepare a dental composite that has a low amount of curing shrinkage and excellent mechanical strength, various 2,2-bis[4-(2-hydroxy-3-methacryloyloxy propoxy) phenyl] propane (Bis-GMA) derivatives were synthesized via molecular structure design, and afterward, properties of their mixtures were explored. Bis-GMA derivatives, which were obtained by substituting methyl groups for hydrogen on the phenyl ring in the Bis-GMA, exhibited lower curing shrinkage than Bis-GMA, whereas their viscosities were higher than that of Bis-GMA. Other Bis-GMA derivatives, which contained a glycidyl methacrylate as a molecular end group exhibited reduced curing shrinkage and viscosity. Methoxy substitution for hydroxyl groups on the Bis-GMA derivatives was performed for the further reduction of the viscosity and curing shrinkage. Various resin mixtures, which had the same viscosity as the commercial one, were prepared, and their curing shrinkage was examined. A resin mixture containing 2,2-bis[3,5-dimethyl, 4-(2-methoxy-3-methacryloyloxy propoxy) phenyl] propane] (TMBis-M-GMA) as a base resin and 4-tert-butylphenoxy-2-methyoxypropyl methacrylate (t-BP-M-GMA) as a diluent exhibited the lowest curing shrinkage among them. The composite prepared from this resin mixture also exhibited the lowest curing shrinkage along with enhanced mechanical properties.
authors.affiliation: School of Chemical Engineering and Materials Science, Chung-Ang University, 221 Huksuk-dong. Dongjak-gu, Seoul 156-756, Korea.
authors.forename: L U
authors.initials: LU
authors.lastname: Kim
authors.forename: J W
authors.initials: JW
authors.lastname: Kim
authors.forename: C K
authors.initials: CK
authors.lastname: Kim
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000138:chemical synthesis / Q000737:chemistry*; D002849:Chromatography, Gas; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials; D003793:Dental Restoration, Permanent; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008422:Materials Testing; D008956:Models, Chemical; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D012116:Resins, Plant; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D001672:Biocompatible Materials; D003188:Composite Resins; D003764:Dental Materials; D011109:Polymethacrylic Acids; D012116:Resins, Plant; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate