Salgado Vinícius Esteves, Borba Mila Metri, Cavalcante Larissa Maria, Moraes Rafael Ratto de, Schneider Luis Felipe
Federal University of Pelotas, Pelotas, RS, Brazil.
J Esthet Restor Dent. 2015 Mar-Apr;27 Suppl 1:S41-8. doi: 10.1111/jerd.12146.
This study aims to determine the influence of photoinitiators' combinations on the hardness, depth of cure, and color of model resin composites.
The composites were formulated by a mixture of BisGMA and triethyleneglycol dimethacrylate (60:40 mol), with barium-aluminum-silicate glass and silicon dioxide particles as inorganic fillers (60 wt%). Three photoinitiator types were tested: camphorquinone/amine (CQ), monoacylphosphine oxide (TPO), and bysacylphosphine oxide (BAPO). Six experimental groups were formed by differences in photoinitiator systems: CQ, TPO, BAPO, CQ+TPO, CQ+BAPO, and CQ+TPO+BAPO. Hardness was determined by Knoop indentation at the top and bottom surfaces (n = 5). Depth of cure was performed according to ISO 4049 scraping method (n = 5). Color was obtained by the CIELAB method (n = 10), 24 hours after curing (baseline), after 30 days storage in distilled water, and after 30 days storage in coffee solution. CIELAB color difference (ΔE*) was calculated for both periods. Data were submitted to analysis of variance, followed by Student-Newman-Keuls method (α = 0.05).
The photoinitiator system influenced hardness, where CQ presented the lowest top and bottom values. No statistical difference among groups was observed for the bottom/top hardness ratio. Regarding the depth of cure, the CQ and those formulated with CQ associations presented higher values than TPO and BAPO. Regarding color, BAPO and CQ+BAPO presented the highest ΔE* after 30 days in water immersion, whereas CQ+TPO and CQ+TPO+BAPO presented the lowest after 30 days in coffee immersion.
The associations CQ+TPO and CQ+TPO+BAPO presented improved color stability and hardness when compared with CQ, and did not influence the depth of cure.
The combination of alternative photoinitiators with the traditional camphorquinone/amine system improved the color stability of the model resin composites and maintaining their mechanical properties.
本研究旨在确定光引发剂组合对模型树脂复合材料的硬度、固化深度和颜色的影响。
复合材料由双酚A双甲基丙烯酸缩水甘油酯（BisGMA）和三乙二醇二甲基丙烯酸酯（60:40摩尔）混合而成，以钡铝硅酸盐玻璃和二氧化硅颗粒作为无机填料（60重量%）。测试了三种光引发剂类型：樟脑醌/胺（CQ）、单酰基氧化膦（TPO）和双酰基氧化膦（BAPO）。通过光引发剂体系的差异形成六个实验组：CQ、TPO、BAPO、CQ+TPO、CQ+BAPO和CQ+TPO+BAPO。通过努氏压痕法测定顶面和底面的硬度（n = 5）。根据ISO 4049刮削法进行固化深度测试（n = 5）。通过CIELAB方法获取颜色（n = 10），在固化后24小时（基线）、在蒸馏水中储存30天后以及在咖啡溶液中储存30天后进行测量。计算两个时间段的CIELAB色差（ΔE*）。数据进行方差分析，随后采用Student-Newman-Keuls方法（α = 0.05）。
光引发剂体系影响硬度，其中CQ的顶面和底面值最低。各实验组之间底面/顶面硬度比未观察到统计学差异。关于固化深度，CQ及其组合配方的固化深度值高于TPO和BAPO。关于颜色，在水浸30天后，BAPO和CQ+BAPO的ΔE最高，而在咖啡浸30天后，CQ+TPO和CQ+TPO+BAPO的ΔE最低。
与CQ相比，CQ+TPO和CQ+TPO+BAPO组合表现出改善的颜色稳定性和硬度，且不影响固化深度。
替代光引发剂与传统樟脑醌/胺体系的组合改善了模型树脂复合材料的颜色稳定性并保持了其机械性能。
