Objective

To determine the influence of benzenesulfinic acid sodium salt 98% (BAS) and the activation mode on the polymerization behavior of experimental self-adhesive resin cements (SARCs) formulated with distinct self-etch methacrylates.

Materials and methods

Three catalyst-pastes using different self-etch methacrylates (2MP — bis 2-(methacryloyloxy) ethyl phosphate; 4META — 4-methacryloxyethyl trimellitic acid anhydride; and GDMAP — 1,3-glycerol dimethacrylate phosphate) and four base-pastes were formulated from the incorporation of different amounts of BAS associated to N-N-dihydroxyethyl-p-toluidine (DHPT). BAS/DHPT ratios were blended respectively based on the following final weight (wt%): control (0.0;2.0%), BP1 (0.5;1.5%), BP2 (0.8;1.2%) and BP3 (1.0;1.0%). Real-time polymerization kinetics (KP) was assessed for 10 min by FTIR spectroscopy. Maximum rate of polymerization (Rp^max) was obtained from the first derivative of the curve conversion versus time. Degree of conversion (DC) was determined over 10 min and after 24 h. SARCs were tested in self and dual activation modes. Data of Rp^max and DC 24 h were respectively analyzed by two-way ANOVA followed by Tukey’s method (α = 0.05).

Results

All factors and their interactions were statistically significant (p < 0.01). BAS caused an increase in DC in the first minutes of the KP analysis, especially in self-activated groups. After 24 h, all groups showed higher DC than those observed in the first 10 min. In general, the addition of BAS increased the Rp^max. The GDMAP-based materials group showed the highest Rp^max values when exposed to light but self-activated formulations with GDMAP or 2MP showed the lowest Rp^max.

Significance

The addition of BAS increased the degree of conversion of SARCs in the first minutes and 24 h after the polymerization reaction. This finding showed the importance of adding this type of salt during resin cement production to achieve better polymerization in the first minutes of the luting procedure specially when light exposure is not possible.

中文翻译：

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酸性钠盐对不同粘合剂单体配制的自粘树脂胶粘剂聚合行为的影响

客观的

为了确定苯磺酸亚硫酸钠98％（BAS）和活化方式对用不同的自蚀刻甲基丙烯酸酯配制的实验自粘树脂水泥（SARC）聚合行为的影响。

材料和方法

使用不同的自蚀刻甲基丙烯酸酯（2MP-双2-（甲基丙烯酰氧基）磷酸乙酯； 4META-4-甲基丙烯酸氧乙基偏苯三酸酐； GDMAP_1，3-甘油二甲基丙烯酸磷酸酯）配制了三种催化剂糊剂，并分别配制了四种碱糊剂不同量关联到BAS的掺入NN -dihydroxyethyl- p -甲苯胺（DHPT）。基于以下最终重量（wt％）分别混合BAS / DHPT比率：对照（0.0； 2.0％），BP1（0.5； 1.5％），BP2（0.8； 1.2％）和BP3（1.0； 1.0％）。通过FTIR光谱评估了10分钟的实时聚合动力学（KP）。聚合的最大速率（RP^最大值从曲线转换的第一导数获得）对时间。在10分钟内和24小时后确定转化度（DC）。SARC已在自激活和双重激活模式下进行了测试。Rp ^max和DC 24 h的数据分别通过双向方差分析和Tukey法（α  = 0.05）进行分析。

结果

所有因素及其相互作用均具有统计学意义（p <0.01）。在KP分析的前几分钟，BAS导致DC升高，尤其是在自我激活的群体中。24小时后，所有组的DC均比前10分钟观察到的高。通常，添加BAS会增加Rp ^max。基于GDMAP的材料组在暴露于光线时显示出最高的Rp ^max值，但具有GDMAP或2MP的自活化配方显示出的最低Rp ^max。

意义

在聚合反应后的最初几分钟和24小时内，BAS的添加提高了SARC的转化度。这一发现表明，在树脂胶粘剂生产过程中添加这种盐的重要性对于在上胶过程的最初几分钟内实现更好的聚合非常重要，特别是在无法进行光暴露的情况下。