Stansbury J W
Dental and Medical Materials Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.
J Dent Res. 1992 Mar;71(3):434-7. doi: 10.1177/00220345920710030201.
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.
合成了一种新型多功能低聚物，并评估了其作为牙科复合配方中基础单体的潜力。通过甲醛插入/缩合反应以良好的产率制备了乙氧基化双酚A二丙烯酸酯（OEBPA）低聚物。尽管沿着低聚物主链的双键成对排列，使得环化聚合成为可能，但目前尚不清楚该过程在聚合中是否起重要作用。支持有效环化聚合的间接证据包括，相对于用作基础树脂的其他单体的聚合物，观察到聚合后的OEBPA的聚合收缩率降低。比较了以OEBPA、双酚A缩水甘油醚（BIS-GMA）或乙氧基化双酚A二甲基丙烯酸酯（EBPADM）作为基础树脂且以三乙二醇二甲基丙烯酸酯（TEGDMA）作为稀释剂的光固化复合材料。虽然所得的径向拉伸强度和横向强度没有显著差异，但失效时吸收的能量值表明，基于OEBPA和EBPADM的配方产生的复合材料比BIS-GMA材料具有更高的韧性。这种多功能低聚物提供的机械强度和转化率值与现有的基础树脂单体相当，同时聚合收缩率降低了约30%。
