Synthesis and evaluation of novel multifunctional oligomers for dentistry.
A new type of multifunctional oligomer was synthesized, and its potential as a base monomer in dental composite formulations was evaluated. The oligomer of ethoxylated bis-phenol A diacrylate (OEBPA) was prepared in good yield by a formaldehyde insertion/condensation reaction. Although double bonds along the oligomer backbone are arranged in pairs such that cyclopolymerization is possible, it is not presently known whether this process plays a significant role in the polymerization. Indirect evidence supporting efficient cyclopolymerization involves the reduced polymerization shrinkage observed for polymerized OEBPA relative to polymers of other monomers used as base resins. Photo-cured composites containing either OEBPA, BIS-GMA, or ethoxylated bis-phenol A dimethacrylate (EBPADM) as base resin and TEGDMA as diluent were compared. While the resulting diametral tensile and transverse strengths did not differ significantly, the values for the energy absorbed to failure indicated that the OEBPA- and EBPADM-based formulations yielded composites with somewhat greater toughness than that of the BIS-GMA material. This multifunctional oligomer offers mechanical strength and conversion values that are comparable with those of existing base resin monomers while providing an approximate 30% reduction in polymerization shrinkage.
Stansbury
J W
JW
Dental and Medical Materials Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.
D017438:Bisphenol A-Glycidyl Methacrylate; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002849:Chromatography, Gas; D003188:Composite Resins / Q000138:chemical synthesis / Q000737:chemistry; D003764:Dental Materials / Q000138:chemical synthesis* / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005069:Evaluation Studies as Topic; D005663:Furans / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008689:Methacrylates / Q000138:chemical synthesis* / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry; D012117:Resins, Synthetic / Q000138:chemical synthesis* / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
D003188:Composite Resins; D003764:Dental Materials; D005663:Furans; D008689:Methacrylates; D011108:Polymers; D012117:Resins, Synthetic; D012997:Solvents; C018674:tetrahydrofuran; C074277:ethoxylated bis-phenol A dimethacrylate; D017438:Bisphenol A-Glycidyl Methacrylate; D004121:Dimethyl Sulfoxide