Universidade Estadual de Campinas - UNICAMP, Faculdade de Odontologia de Piracicaba, Departamento de Odontologia Restauradora, Piracicaba, SP, Brasil.
Universidade Federal do Rio de Janeiro, Instituto de Macromoléculas Professora Eloisa Mano, Rio de Janeiro, RJ, Brasil.
J Appl Oral Sci. 2021 Jul 23;29:e20200467. doi: 10.1590/1678-7757-2020-0467. eCollection 2021.
Camphorquinone is the most conventionally used photoinitiator in Dentistry. Although different alternative photoinitiators have been proposed, no photoinitiator was capable of completely substituting camphorquinone. The combination of photoinitiators has been considered the best alternative.
To evaluate the effect of combining Norrish type I and II photoinitiators on the cure efficiency of dental resin-based composites.
Experimental composites were produced containing different photoinitiator systems: Norrish type I-only, mono-alkyl phosphine oxide (TPO); Norrish type II-only, camphorquinone (CQ); or its combination, CQ and TPO, in a 1: 1 molar ratio. UV-vis absorption spectrophotometry was performed to assess the consumption of each photoinitiator after curing (n=3). A multi-wave LED (Bluephase® G2, Ivoclar Vivadent) was pre-characterized and used with a radiant exposure of 24 J/cm2. The degree of conversion was evaluated by Raman spectrometry, and the elution of the monomers by nuclear magnetic resonance analysis (n=3). Data were analyzed using ANOVA and Tukey's test (α=0.05; β=0.2).
The combination of CQ and TPO increased the consumption of the photoinitiator system compared to CQ-only (p=0.001), but presented similar consumption compared to TPO-only (p=0.52). There was no significant difference in the degree of conversion between the composites regardless of the photoinitiator system (p=0.81). However, the elution of the monomers was reduced when both photoinitiators were combined. TPO-based material presented the highest elution of monomers.
The combination of the photoinitiator systems seems to be beneficial for the cure efficiency of dental resin-based composites.
樟脑醌是牙科最常用的光引发剂。尽管已经提出了不同的替代光引发剂，但没有一种光引发剂能够完全替代樟脑醌。组合使用光引发剂被认为是最好的替代方法。
评估 Norrish 型 I 和 II 光引发剂组合对牙科树脂基复合材料固化效率的影响。
实验性复合材料中含有不同的光引发剂系统：仅 Norrish 型 I，单烷基亚膦氧化物（TPO）；仅 Norrish 型 II，樟脑醌（CQ）；或其摩尔比为 1:1 的组合，CQ 和 TPO。使用紫外可见吸收光谱法评估固化后每种光引发剂的消耗（n=3）。多波长 LED（Bluephase® G2，Ivoclar Vivadent）进行了预特性化，并使用 24 J/cm2 的辐射暴露。通过拉曼光谱评估转化率，通过核磁共振分析（n=3）评估单体的洗脱。使用方差分析和 Tukey 检验（α=0.05；β=0.2）对数据进行分析。
与仅 CQ 相比，CQ 和 TPO 的组合增加了光引发剂系统的消耗（p=0.001），但与仅 TPO 相比，其消耗相似（p=0.52）。无论光引发剂系统如何，复合材料的转化率均无显着差异（p=0.81）。然而，当两种光引发剂结合使用时，单体的洗脱量减少。基于 TPO 的材料表现出最高的单体洗脱量。
光引发剂系统的组合似乎有利于牙科树脂基复合材料的固化效率。
