Rodrigues Stéfani Becker, Collares Fabrício Mezzomo, Leitune Vicente Castelo Branco, Schneider Luis Felipe Jochims, Ogliari Fabrício Aulo, Petzhold Cesar Liberato, Samuel Susana Maria Werner
Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Dental Materials Laboratory, School of Dentistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
Dent Mater. 2015 Dec;31(12):1579-86. doi: 10.1016/j.dental.2015.10.005. Epub 2015 Nov 6.
to determine the physicochemical properties of experimental adhesive resins containing hydroxyethyl acrylamide.
Three groups of experimental resin were formulated, GHEAA33% (33.3wt% HEAA+66.6wt% BisGMA), GHEAA50% (50wt% HEAA+50wt% BisGMA), and GHEAA-FREE (33.3wt% HEMA+66.6wt% of BisGMA). The polymerization process of each adhesive resin group, as well as for the homopolymers, BisGMA, HEMA, HEAA, HEMA* without EDAB, and HEAA* without EDAB, was characterized through differential scanning calorimetry (DSC). Elution of monomers was evaluated by (1)H NMR. Dynamic mechanical analysis (DMA) was used to collect the glass transition temperature (Tg), the storage modulus (E') and the reticulation degree (ρ). Flexural strength was calculated by three-point bending test with 0.75mm/min. Softening in solvent was calculated through hardness before and after immersion in water or ethanol.
GHEAA50%, GHEAA33%, GHEAA-FREE presented higher polymerization rate ( [Formula: see text] , 12.3 and 5.3mmolg(-1)s(-1), respectively) than homopolymers HEMA, HEMA* and HEAA*. Group with HEAA presented higher degree of conversion (GHEAA50%=64.07%>GHEAA33%=55.82%>GHEAA-FREE=49.02%; p=0.008) All groups presented low elution of monomers (p>0.05). The values of E' were higher on GHEAA33% than GHEAA-FREE (p=0.034). Tg and flexural strength values of GHEAA-FREE were higher than acrylamide groups (p=0.022 and p<0.001, respectively). Hardness varied from 27.05 to 34.78 for water and from 63.27 to 68.51 for ethanol with no difference for ρ values.
The addition of HEAA increased the materials reactivity and, consequently, improved the maximum rate of polymerization, degree of conversion and the storage modulus of experimental adhesive resin.
测定含羟乙基丙烯酰胺的实验性粘结树脂的物理化学性质。
配制三组实验性树脂，即GHEAA33%（33.3wt%羟乙基丙烯酰胺+66.6wt%双甲基丙烯酸缩水甘油酯）、GHEAA50%（50wt%羟乙基丙烯酰胺+50wt%双甲基丙烯酸缩水甘油酯）和不含羟乙基丙烯酰胺组（33.3wt%甲基丙烯酸羟乙酯+66.6wt%双甲基丙烯酸缩水甘油酯）。通过差示扫描量热法（DSC）对各粘结树脂组以及均聚物、双甲基丙烯酸缩水甘油酯、甲基丙烯酸羟乙酯、羟乙基丙烯酰胺、不含二乙胺基苯甲酸的甲基丙烯酸羟乙酯和不含二乙胺基苯甲酸的羟乙基丙烯酰胺的聚合过程进行表征。通过¹H NMR评估单体的洗脱情况。采用动态力学分析（DMA）来测定玻璃化转变温度（Tg）、储能模量（E'）和交联度（ρ）。通过三点弯曲试验，以0.75mm/min的速度计算弯曲强度。通过测定在水或乙醇中浸泡前后的硬度来计算在溶剂中的软化情况。
GHEAA50%、GHEAA33%、不含羟乙基丙烯酰胺组的聚合速率（分别为[公式：见原文]、12.3和5.3mmol g⁻¹ s⁻¹）高于均聚物甲基丙烯酸羟乙酯、不含二乙胺基苯甲酸的甲基丙烯酸羟乙酯和不含二乙胺基苯甲酸的羟乙基丙烯酰胺。含羟乙基丙烯酰胺的组具有更高的转化率（GHEAA50% = 64.07% > GHEAA33% = 55.82% > 不含羟乙基丙烯酰胺组 = 49.02%；p = 0.008）。所有组的单体洗脱量均较低（p > 0.05）。GHEAA33%的E'值高于不含羟乙基丙烯酰胺组（p = 0.034）。不含羟乙基丙烯酰胺组的Tg和弯曲强度值高于丙烯酰胺组（分别为p = 0.022和p < 0.001）。水的硬度在27.05至34.78之间，乙醇的硬度在63.27至68.51之间，ρ值无差异。
羟乙基丙烯酰胺的添加提高了材料的反应活性，从而提高了实验性粘结树脂的最大聚合速率、转化率和储能模量。
