Photoinitiator type and applicability of exposure reciprocity law in filled and unfilled photoactive resins
Photoinitiator type and applicability of exposure reciprocity law in filled and unfilled photoactive resins
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DOI：
10.1016/j.dental.2010.09.011
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发表时间：
2011-02-01
期刊：
影响因子：
5
通讯作者：
Palin, W. M.
中科院分区：
文献类型：
--
作者：
Leprince, J. G.;Hadis, M.;Palin, W. M.
目标.测试光引发剂类型和填料颗粒对曝光互易定律有效性的影响。材料和方法。用等摩尔浓度的邻苯二酚/DMAEMA（0.20/0.80质量%）（CQ）或Lucirin-TPO（0.42质量%）制备50/50重量%的Bis-GMA/TEGDMA树脂，并且未填充或填充至75质量%使用。使用四种不同的固化方案用卤素Swiss Master Light（EMS，瑞士）固化样本：400 mW/cm（2）持续45秒作为参考方案（18 J/cm（2）），1500 mW/cm（2）持续12秒（18 J/cm 2），3000 mW/cm（2）持续6秒（18 J/cm 2）和3秒（9 J/cm 2）。通过FT-NIRS和使用热电偶的温度上升在真实的时间内测量转化度（DC）70 s。固化的深度是用一个certrometer技术来确定。对于DC和固化深度，暴露互易定律不适用于任何测试材料，除了填充CQ基材料的固化深度。在相似的辐射暴露下，与CQ基材料相比，所有未填充和填充的TPO基材料的DC显著更高（p < 0.05）。随着暴露时间的减少和辐照度的增加，TPO基材料表现出更高的DC，而CQ基材料观察到相反的趋势（p < 0.05）。对于类似的固化制度，CQ基材料的固化深度仍然显着大于TPO基材料的固化深度。添加填充物通常降低DC，除了在较高辐照度下观察到基于CQ的材料的正效应（p < 0.05）。曝光互易定律的有效性取决于多种因素，其中光引发剂类型和填料含量是重要的。Lucirin-TPO是一种高反应性和高效的光引发剂，其可以允许减少薄切片中TPO基光活性材料的固化时间的潜力。(C)2010年牙科材料学院。由爱思唯尔有限公司出版。保留所有权利。
Objectives. To test the influence of photoinitiator type and filler particle inclusion on the validity of exposure reciprocity law.Materials and methods. 50/50 wt% Bis-GMA/TEGDMA resins were prepared with equimolar concentrations of camphorquinone/DMAEMA (0.20/0.80 mass%) (CQ) or Lucirin-TPO (0.42 mass%), and were used either unfilled or filled to 75 mass%. Specimens were cured with a halogen Swiss Master Light (EMS, Switzerland) using four different curing protocols: 400mW/cm(2) for 45 s as reference protocol (18 J/cm(2)), 1500mW/cm(2) for 12 s (18 J/cm2), 3000mW/cm(2) for 6 s (18 J/cm2) and 3 s (9 J/cm2). Degree of conversion (DC) was measured in real time for 70 s by FT-NIRS and temperature rise using a thermocouple. Depth of cure was determined with a penetrometer technique.Results. With respect to DC and depth of cure, exposure reciprocity law did not hold for any tested material, except for the depth of cure of filled CQ-based materials. At similar radiant exposure, DC was significantly higher (p < 0.05) for all unfilled and filled TPO-based materials compared with CQ-based materials. As exposure time was reduced and irradiance increased, TPO-based materials exhibited higher DC whilst an opposite trend was observed for CQ based materials (p < 0.05). For similar curing regimes, depth of cure of CQ-based materials remained significantly greater than that of TPO-based materials. Adding fillers generally reduced DC, except at higher irradiance for CQ-based materials where a positive effect was observed (p < 0.05).Significance. The validity of exposure reciprocity law was dependent on several factors, among which photoinitiator type and filler content were important. Lucirin-TPO is a highly reactive and efficient photoinitiator, which may allow the potential for a reduction in curing time of TPO-based photoactive materials in thin sections. (C) 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.