Skrtic D, Stansbury J W, Antonucci J M
American Dental Association Health Foundation-Paffenbarger Research Center, National Institute of Standards and Technology, 100 Bureau Drive Stop 8546, Gaithersburg, MD 20899-8546, USA.
Biomaterials. 2003 Jun;24(14):2443-9. doi: 10.1016/s0142-9612(02)00574-4.
Because of its relatively high solubility in aqueous media and its rapid transformation to hydroxyapatite, amorphous calcium phosphate (ACP) has been utilized as the filler phase of resin-based bioactive composites that have remineralization potential. The objectives of this study were to determine how various methacrylate resins and various types of ACP fillers affect acrylic vinyl conversion and polymerization shrinkage (PS). Several types of photo-crosslinkable resin systems were prepared and admixed with a mass fraction of 40% of either unhybridized, silica- or zirconia-hybridized ACP. After visible light-activated photo-polymerization ACP composites were assessed by near infrared spectroscopy for degree of vinyl conversion and by mercury dilatometry for PS. It was found for these composites that vinyl conversion was independent of filler type but strongly dependent on the type and composition of the resin phase. PS, on the other hand, showed more complex dependence both on the resin type and composition and, in some cases, on the type of ACP. In order to obtain ACP/methacrylate-based composites with maximal vinyl conversion, resin type and composition are of primary importance. However, in order to minimize volume contraction on polymerization it appears necessary to consider both the resin and filler type of these bioactive composites.
由于无定形磷酸钙（ACP）在水性介质中具有相对较高的溶解度，且能迅速转化为羟基磷灰石，因此它已被用作具有再矿化潜力的树脂基生物活性复合材料的填充相。本研究的目的是确定各种甲基丙烯酸酯树脂和各种类型的ACP填料如何影响丙烯酸乙烯基转化率和聚合收缩率（PS）。制备了几种类型的可光交联树脂体系，并与质量分数为40%的未杂化、二氧化硅或氧化锆杂化的ACP混合。在可见光激活光聚合后，通过近红外光谱法评估ACP复合材料的乙烯基转化率，通过汞膨胀计评估PS。结果发现，对于这些复合材料，乙烯基转化率与填料类型无关，但强烈依赖于树脂相的类型和组成。另一方面，PS对树脂类型和组成以及在某些情况下对ACP类型表现出更复杂的依赖性。为了获得具有最大乙烯基转化率的基于ACP/甲基丙烯酸酯的复合材料，树脂类型和组成至关重要。然而，为了使聚合时的体积收缩最小化，似乎有必要考虑这些生物活性复合材料的树脂和填料类型。
