Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Rua Ramiro Barcelos, 2492, Rio Branco, 90035-003, Porto Alegre, RS, Brazil.
J Dent. 2019 Nov;90:103208. doi: 10.1016/j.jdent.2019.103208. Epub 2019 Oct 7.
To develop experimental light-cured (L) and dual-cured (D) resin cements containing N-(2-hydroxyethyl)acrylamide and evaluate the physicochemical and optical properties.
Experimental resin cements were formulated using bisphenol A-glycidyl dimethacrylate (70%) and 2-hydroxyethyl methacrylate (30%), in the control groups, and, bisphenol A-glycidyl dimethacrylate (70%) and N-(2-hydroxyethyl)acrylamide (30%). Polymerization kinetics were evaluated by differential scanning calorimetry (n = 3), softening in solvent (ΔKHN) evaluated by the difference of Knoop microhardness before (KHN) and after (KHN) ethanol solution immersion (n = 5), radiopacity in mmAl (n = 5), film thickness (n = 3) and color stability were evaluated. Mechanical properties as ultimate tensile strength (UTS) and micro-shear bond strength (μSBS) were analyzed immediately and after 6 months. Results were analyzed using ANOVA, Tukey's test and Student's t-test (α = 0.050).
The L group had no statistical difference from the control group regarding polymerization kinetics, KHN, ΔKHN and color stability (p > 0.050). In dual-cured cements, the acrylamide groups presented a lower degree of conversion and higher ΔKHN than the D group, which obtained a higher rate of polymerization (p < 0.050). There was no statistical difference in radiopacity and film thickness (p > 0.050). Dual-cured cements with N-(2-hydroxyethyl)acrylamide showed higher color change than methacrylates. Immediate mechanical properties were lower for acrylamide groups (p < 0.050), with higher hydrolytic stability.
The addition of N-(2-hydroxyethyl)acrylamide negatively affected the properties of the dual-cured resin cements. LHEAA1 did not differ in physicochemical and optical properties from the control, with higher hydrolytic stability.
The results of the study indicate that acrylamides increased mechanical properties over time independently of the curing system mode, with more hydrolytic stability. The clinical performance of experimental resin cements should be evaluated.
开发含有 N-(2-羟乙基)丙烯酰胺的实验光固化（L）和双重固化（D）树脂水泥，并评估其物理化学和光学性能。
在对照组中，使用双酚 A-缩水甘油二甲基丙烯酸酯（70%）和 2-羟乙基甲基丙烯酸酯（30%），在实验组中，使用双酚 A-缩水甘油二甲基丙烯酸酯（70%）和 N-(2-羟乙基)丙烯酰胺（30%）来配制实验性树脂水泥。通过差示扫描量热法（n=3）评估聚合动力学，通过比较乙醇溶液浸泡前后的努普硬度（KHN）差值（KHN）评估软质溶剂（ΔKHN）（n=5），通过 mmAl 评估射线不透性（n=5），通过薄膜厚度（n=3）评估颜色稳定性。即刻和 6 个月后分析机械性能，如极限拉伸强度（UTS）和微剪切粘结强度（μSBS）。使用方差分析、Tukey 检验和学生 t 检验（α=0.050）分析结果。
L 组在聚合动力学、KHN、ΔKHN 和颜色稳定性方面与对照组无统计学差异（p>0.050）。在双重固化水泥中，丙烯酰胺组的转化率和 ΔKHN 均低于 D 组，而 D 组的聚合速率更高（p<0.050）。射线不透性和薄膜厚度无统计学差异（p>0.050）。含 N-(2-羟乙基)丙烯酰胺的双重固化水泥的颜色变化大于甲基丙烯酸酯。丙烯酰胺组的即刻机械性能较低（p<0.050），水解稳定性较高。
添加 N-(2-羟乙基)丙烯酰胺会降低双重固化树脂水泥的性能。LHEAA1 在物理化学和光学性质上与对照组无差异，水解稳定性更高。
研究结果表明，丙烯酰胺在不依赖固化系统模式的情况下，随时间推移提高机械性能，具有更高的水解稳定性。应评估实验性树脂水泥的临床性能。
