Objective

To evaluate the influence of different co-initiators (diphenyliodonium hexafluorophosphate - DPI - and bis(4-methyl phenyl)iodonium hexafluorophosphate – BPI) on chemical and mechanical properties of resins.

Methods

Nine experimental resins (50% Bis-GMA and 50% TEGDMA, w/w) with 60 wt% filler particles were formulated. The initiating system used was camphorquinone (CQ-1 mol%) and ethyl dimethylaminobenzoate (EDAB-2 mol%). Experimental groups were established according to DPI and BPI quantities (0.25, 0.5, 0.75, and 1 mol%). The control group was a resin containing only CQ-EDAB. Light transmission through the resin during polymerisation was analysed with a UV–vis spectrophotometer. Real-time polymerisation of the systems was evaluated using an FTIR spectrometer. Real-time polymerisation shrinkage strain was evaluated, and the flexural strength and modulus of materials were obtained by 3-point bending. Experimental groups were statistically analysed by Analysis of Variance and Tukey’s test (α = 0.05). Dunnett’s test was applied to compare experimental groups with control.

Results

Light transmission rapidly increased initially for resins containing DPI or BPI. After 30 s cure, the irradiance on the lower surface of resin specimens was similar for all groups. After 10 s of light irradiation, groups containing DPI and BPI had higher conversion than the control. However, conversion after 120 s post-irradiation was similar for all groups. The rate of polymerisation, shrinkage strain, and the maximum strain rate were higher for groups containing DPI/BPI. The use of iodonium salts increased the flexural strength and flexural moduli of resins.

Significance

DPI and BPI increased resin reactivity similarly. Increased rate of polymerization influenced light transmission through the resin in the first seconds of polymerisation and increased resin shrinkage and rate of shrinkage, as well as flexural strength and moduli.

中文翻译：

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在基于樟脑醌的三元引发体系中，双（4-甲基苯基）碘作为二苯基碘的替代组分。

目的

评估不同的共引发剂（六氟磷酸二苯基碘鎓-DPI和六氟磷酸双（4-甲基苯基）碘鎓-BPI）对树脂化学和机械性能的影响。

方法

配制了具有60 wt％填料颗粒的九种实验树脂（50％Bis-GMA和50％TEGDMA，w / w）。所使用的引发体系是樟脑醌（CQ-1mol％）和二甲基氨基苯甲酸乙酯（EDAB-2mol％）。根据DPI和BPI量（0.25、0.5、0.75和1摩尔％）建立实验组。对照组是仅含有CQ-EDAB的树脂。用紫外可见分光光度计分析了聚合过程中通过树脂的透光率。使用FTIR光谱仪评估系统的实时聚合。评价实时聚合收缩应变，并通过三点弯曲获得材料的弯曲强度和模量。实验组通过方差分析和Tukey检验（α= 0.05）。Dunnett检验用于比较实验组和对照组。

结果

最初，含有DPI或BPI的树脂的透光率迅速提高。固化30秒后，所有组在树脂样品下表面的辐照度均相似。光照10秒后，含DPI和BPI的组的转化率高于对照。但是，所有组辐照后120 s后的转化率均相似。含有DPI / BPI的组的聚合速率，收缩应变和最大应变速率较高。碘鎓盐的使用增加了树脂的弯曲强度和弯曲模量。

意义

DPI和BPI相似地提高了树脂的反应性。聚合速率的提高影响了聚合反应刚开始的几秒钟内通过树脂的透光率，并增加了树脂的收缩率和收缩率，以及挠曲强度和模量。