Department of Restorative Dentistry, Dental Materials Area, University of Brasília-UnB, DF, Brazil.
J Dent. 2010 Jan;38(1):44-9. doi: 10.1016/j.jdent.2009.09.003.
This study examined the retention of solvents within experimental HEMA/solvent primers after two conditions for solvent evaporation: from a free surface or from dentine surface.
Experimental primers were prepared by mixing 35% HEMA with 65% water, methanol, ethanol or acetone (v/v). Aliquots of each primer (50 microl) were placed on glass wells or they were applied to the surface of acid-etched dentine cubes (2mm x 2mm x 2mm) (n=5). For both conditions (i.e. from free surface or dentine cubes), change in primers mass due to solvent evaporation was gravimetrically measured for 10min at 51% RH and 21 degrees C. The rate of solvent evaporation was calculated as a function of loss of primers mass (%) over time. Data were analysed by two-way ANOVA and Student-Newman-Keuls (p<0.05).
There were significant differences between solvent retention (%) and evaporation rate (%/min) depending on the solvent present in the primer and the condition for evaporation (from free surface or dentine cubes) (p<0.05). For both conditions, the greatest amount of retained solvent was observed for HEMA/water primer. The rate of solvent evaporation for HEMA/acetone primer was almost 2- to 10-times higher than for HEMA/water primer depending whether evaporation occurred, respectively, from a free surface or dentine cubes. The rate of solvent evaporation varied with time, being in general highest at the earliest periods.
The rate of solvent evaporation and its retention into HEMA/solvent primers was influenced by the type of the solvent and condition allowed for their evaporation.
本研究考察了在两种溶剂蒸发条件下（从自由表面或牙本质表面），实验性 HEMA/溶剂底漆中溶剂的保留情况。
通过将 35%的 HEMA 与 65%的水、甲醇、乙醇或丙酮（v/v）混合制备实验性底漆。将每种底漆的等分试样（50 微升）置于玻璃井中，或将其涂覆在酸蚀牙本质立方体（2mm x 2mm x 2mm）的表面上（n=5）。对于两种条件（即从自由表面或牙本质立方体），在 51%RH 和 21°C 的条件下，通过重量法测量由于溶剂蒸发而导致的底漆质量变化，持续 10 分钟。将溶剂蒸发率计算为随着时间的推移损失的底漆质量（%）的函数。通过双因素方差分析和 Student-Newman-Keuls 检验（p<0.05）对数据进行分析。
根据底漆中存在的溶剂和蒸发条件（从自由表面或牙本质立方体）的不同，溶剂保留（%）和蒸发率（%/min）之间存在显著差异（p<0.05）。对于两种条件，在 HEMA/水底漆中观察到最大量的保留溶剂。HEMA/丙酮底漆的溶剂蒸发率几乎是 HEMA/水底漆的 2 至 10 倍，具体取决于蒸发分别从自由表面或牙本质立方体进行。溶剂蒸发率随时间变化而变化，在早期通常最高。
溶剂蒸发率及其在 HEMA/溶剂底漆中的保留情况受溶剂类型和允许其蒸发的条件的影响。
