The effect of photopolymerization on the degree of conversion, polymerization kinetic, biaxial flexure strength, and modulus of self-adhesive resin cements
The effect of photopolymerization on the degree of conversion, polymerization kinetic, biaxial flexure strength, and modulus of self-adhesive resin cements
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DOI：
10.1016/j.prosdent.2014.09.011
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发表时间：
2015-02-01
影响因子：
4.6
通讯作者：
Giannini, Marcelo
中科院分区：
文献类型：
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作者：
Aguiar, Thaiane R.;de Oliveira, Michele;Giannini, Marcelo
问题陈述。了解转化程度对自聚合和双聚合自粘性树脂粘固剂机械性能的影响，可以更好地评估其在不同临床应用中的性能。目的。本研究的目的是评估光聚合对4种双聚合树脂水门汀混合后20分钟的转化度（DC）和聚合动力学的影响，以及其对短期老化后机械性能（双轴弯曲强度[FS]和模量[FM]）的影响。将传统（RelyX ARC和Clearfil美学骨水泥）和自粘性树脂骨水泥（RelyX Unicem和Clearfil SA骨水泥）应用于傅立叶红外光谱仪，以评估以下3种聚合条件下的DC（n=5）：直接曝光（双聚合模式）、通过预聚合盘曝光或自聚合。记录聚合动力学20分钟。然后，制备盘形试样（n=11）以评估在两种极端聚合条件（双聚合或自聚合）下聚合对FS和FM的影响。通过双向重复测量ANOVA（DC）和双向ANOVA（FS和FM）对数据进行统计学分析，然后进行Tukey-Kramer事后检验（α =.05）。自聚合组表现出减少DC的手段，而中间值时，观察到树脂水泥聚合通过磁盘。所有组在20分钟结束时均表现出较高的DC。聚合动力学揭示了一个上升曲线，和材料，直接光聚合时，达到一个平台曝光后立即。对于弯曲双轴测试，大多数树脂粘固剂受聚合模式的影响，组间差异与产品有关。树脂水门汀实现即时较高的DC和机械性能时，光聚合。即使在短期老化后，完全不存在光活化仍然可能损害其机械性能。
Statement of problem. Understanding the effect of the degree of conversion on the mechanical properties of auto- and dual-polymerizing self-adhesive resin cements leads to a better estimation of their performance in different clinical scenarios.Purpose. The purpose of this study was to evaluate the effect of photopolymerization on the degree of conversion (DC) and polymerization kinetic of 4 dual-polymerized resin cements, 20 minutes after mixing, and its effects on the mechanical properties (biaxial flexural strength [FS] and modulus [FM]) after short-term aging.Material and methods. Conventional (RelyX ARC and Clearfil Esthetic Cement) and self-adhesive resin cements (RelyX Unicem and Clearfil SA Cement) were applied to a Fourier infrared spectrometer to assess the DC (n=5) under the following 3 polymerization conditions: direct light exposure (dual-polymerizing mode), exposure through the prepolymerized disk, or autopolymerizing. The polymerization kinetic was recorded for 20 minutes. Then, disk-shaped specimens (n=11) were prepared to evaluate the effect of polymerization on the FS and FM in both extreme polymerization conditions (dual-polymerizing or autopolymerizing). Data were statistically analyzed by 2-way repeated measure ANOVA (DC) and by 2-way ANOVA (FS and FM), followed by the Tukey-Kramer post hoc test (alpha=.05).Results. Autopolymerizing groups exhibited reduced DC means, whereas intermediate values were observed when resin cements were polymerized through the disk. All groups exhibited higher DC at the end of 20 minutes. The polymerization kinetic revealed a rising curve, and materials, when directly photopolymerized, reached a plateau immediately after light exposure. Regarding the flexural biaxial testing, most of the resin cements were affected by polymerization mode and differences among groups were product dependent.Conclusions. The resin cements achieved immediate higher DC and mechanical properties when photopolymerized. The total absence of photoactivation may still impair their mechanical properties even after short-term aging.