Skrtic D, Antonucci J M, McDonough W G, Liu D W
Paffenbarger Research Center, American Dental Association Foundation, National Institute of Standards and Technology, 100 Bureau Drive, Stop 8456, Gaithersburg, Maryland 20899-8456, USA.
J Biomed Mater Res A. 2004 Mar 15;68(4):763-72. doi: 10.1002/jbm.a.20111.
The mechanical properties of recently developed bioactive, antidemineralizing/remineralizing, amorphous calcium phosphate (ACP)-based composites need improvement. The objective of this study was to elucidate the effect of structure and composition of resins on the biaxial flexure strength (BFS) and the degree of conversion (DC) of composites attained after photo-polymerization. Two series of 2,2-bis[p-(2'-hydroxy-3'-methacryloxypropoxy)phenyl]propane (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA)/X (X being a neutral or acidic comonomer) ternary resins were prepared and mixed with a mass fraction of 40% of zirconia-hybridized ACP. Both unfilled copolymers and their composites were evaluated for BFS (dry and wet specimens after 2 weeks of immersion in buffered saline) and for DC (after 24 h at 23 degrees C). It was found that for the neutral X monomers, no correlation existed between the hydrophobic/hydrophilic character of the X monomer and the BFS values of the immersed composites. A flexible monomethacrylate yielded copolymers and composites with the highest DC. For the resins utilizing the acidic comonomers, methacrylic acid and mono-4-(methacryloyloxy) ethyltrimellitate (4MET), dry composites with improved BFS values were obtained. 4MET composites exhibited the least loss of strength of all the ternary resin ACP materials. The effect of acidic X on DC was most pronounced for maleic acid copolymers.
最近开发的基于生物活性、抗脱矿质/再矿化的无定形磷酸钙（ACP）复合材料的机械性能有待提高。本研究的目的是阐明树脂的结构和组成对光聚合后复合材料的双轴弯曲强度（BFS）和转化率（DC）的影响。制备了两个系列的2,2-双[p-(2'-羟基-3'-甲基丙烯酰氧基丙氧基)phenyl]丙烷（Bis-GMA）/三乙二醇二甲基丙烯酸酯（TEGDMA）/X（X为中性或酸性共聚单体）三元树脂，并与质量分数为40%的氧化锆杂化ACP混合。对未填充的共聚物及其复合材料进行了BFS（在缓冲盐水中浸泡2周后的干燥和湿样品）和DC（在23℃下24小时后）评估。结果发现，对于中性X单体，X单体的疏水/亲水特性与浸泡后复合材料的BFS值之间不存在相关性。一种柔性单甲基丙烯酸酯产生了DC最高的共聚物和复合材料。对于使用酸性共聚单体甲基丙烯酸和单-4-(甲基丙烯酰氧基)乙基偏苯三酸酯（4MET）的树脂，获得了具有改善BFS值的干燥复合材料。4MET复合材料在所有三元树脂ACP材料中强度损失最小。酸性X对DC的影响在马来酸共聚物中最为明显。
