Development of aesthetic light-activated restorative resin using a new photoinitiation system

可见光活化复合树脂因其操作简单、美观、物理机械性能好等优点，被广泛应用于牙科直接充填修复材料中。考虑到紫外光的不利生物效应，樟脑酚(CQ)作为可见光活化树脂的光引发剂已在牙科中被接受，因为它吸收无害的可见蓝光区域的波长。但CQ存在聚合效率低、呈纯黄色等缺点，会导致树脂的力学性能下降，最终聚合树脂会出现不理想的泛黄现象。这对树脂中CQ的可接受浓度施加了实际限制。为了克服CQ的缺点，一些替代的可见光引发剂被引入到牙科光活化树脂中作为光引发剂，与CQ相比，这些光引发剂具有更低的黄变效应和更高的聚合效率。本研究在不降低树脂性能的前提下，考察了苯基丙二酮、单酰基氧膦和双酰基氧膦等多种新型光引发剂替代CQ的效果。此外，还比较了不同光引发剂对光活化树脂的显色效果和对CQ的影响。结果表明，与CQ和其他光引发剂相比，单酰基氧化膦光引发剂为牙科光活化树脂提供了一种有用的和改进的光聚合体系，并且聚合过程和聚合后的颜色变化较小。

Visible light-activated composite resins has been widely used in dentistry as direct filling restorative materials because of their easy handling, aesthetics, and improved physical and mechanical properties. Considering the adverse biological effects of UV light, the use of camphorquinone (CQ) as a photoinitiator for the visible light-activated resin has been accepted in dentistry, because it absorbs wavelengths in the harmless visible blue-light region. However, CQ has some drawbacks such as low polymerization efficiency and its solid yellow, which would result in low mechanical properties of the resin, and lead to undesirable yellowing of the final polymerized resin. This places practical limits on the acceptable concentration of CQ in the resin. To overcome the drawbacks of CQ, some alternative visible light photoinitiators have been introduced for dental light-activated resins as the photoinitiators, which have desirable benefits such as a lower yellowing effect and higher polymerization efficiency compared with CQ. This study investigated the efficacy of alternative various new photoinitiators, such as phenylpropadione, monoacylphosphine oxide, and bisacylphosphine oxide, which would replace CQ without diminishing the properties of resin. In addition, the color effects of the alternative photoinitiators on the light-activated resin were compared to that of CQ. Our results indicate that the monoacylphosphine oxide photoinitiator provided a useful and improved photopolymerization system for dental light-activated resins, and also showed less of a color change during and after polymerization in comparison with CQ and other photoinitiators.