Pashley D H, Agee K A, Nakajima M, Tay F R, Carvalho R M, Terada R S, Harmon F J, Lee W K, Rueggeberg F A
Department of Oral Biology and Maxillofacial Pathology, School of Dentistry, Medical College of Georgia, Augusta, GA 30912, USA.
J Biomed Mater Res. 2001 Aug;56(2):273-81. doi: 10.1002/1097-4636(200108)56:2<273::aid-jbm1095>3.0.co;2-a.
The purpose of this study was to test the null hypothesis that the re-expansion of dried matrix and the shrinkage of moist, demineralized dentin is not influenced by polar solvents. Dentin disks were prepared from midcoronal dentin of extracted human third molars. After complete demineralization in 0.5M of EDTA (pH 7), the specimens were placed in the well of a device that measures changes in matrix height in real time. Dry, collapsed matrices were created by blowing dry N(2) on the specimens until they shrank to a stable plateau. Polar solvents [water, methanol, ethanol, n-propanol, n-butanol, formamide, ethylene glycol, hydroxyethyl methacrylate (HEMA), or mixtures of water-HEMA] as model primers then were added and the degree of re-expansion measured. These same solvents also were applied to moist, expanded matrices and the solvent-induced shrinkages measured. Regression analysis was used to test the correlations between matrix height and Hansen's dispersive, polar, hydrogen bonding, and total solubility parameters (delta(d), delta(p), delta(h), delta(t)). The results indicate that water-free polar solvents of low hydrogen bonding (H-bond) ability (e.g., neat HEMA) do not re-expand dried matrices and that they shrink moist matrices. When HEMA was mixed with progressively higher water concentrations, the model water-HEMA primers expanded the dried matrix in proportion to their water concentrations and they produced less shrinkage of moist matrices. Solvents with higher H-bonding capacities (methanol, ethanol, ethylene glycol, formamide, and water) re-expanded the dried matrix in proportion to their solubility parameters for H-bonding (delta(h)). They also induced small transient shrinkages of moist matrices, which slowly re-expanded. The results require rejection of the null hypothesis.
本研究的目的是检验零假设，即干燥基质的再膨胀以及湿润、脱矿牙本质的收缩不受极性溶剂的影响。从拔除的人类第三磨牙的冠中牙本质制备牙本质盘。在0.5M乙二胺四乙酸（pH 7）中完全脱矿后，将标本置于可实时测量基质高度变化的装置的孔中。通过向标本吹干燥氮气直至其收缩至稳定平台来创建干燥、塌陷的基质。然后添加极性溶剂[水、甲醇、乙醇、正丙醇、正丁醇、甲酰胺、乙二醇、甲基丙烯酸羟乙酯（HEMA）或水-HEMA混合物]作为模型引发剂，并测量再膨胀程度。这些相同的溶剂也应用于湿润、膨胀的基质，并测量溶剂诱导的收缩。使用回归分析来测试基质高度与汉森色散、极性、氢键和总溶解度参数（δ(d)、δ(p)、δ(h)、δ(t)）之间的相关性。结果表明，低氢键（H键）能力的无水极性溶剂（例如纯HEMA）不会使干燥的基质再膨胀，并且它们会使湿润的基质收缩。当HEMA与逐渐增加的水浓度混合时，模型水-HEMA引发剂会根据其水浓度使干燥的基质膨胀，并且它们使湿润基质的收缩更小。具有较高氢键能力的溶剂（甲醇、乙醇、乙二醇、甲酰胺和水）会根据其氢键溶解度参数（δ(h)）使干燥的基质再膨胀。它们还会引起湿润基质的小的瞬时收缩，然后缓慢再膨胀。结果需要拒绝零假设。
