Department of Restorative Dentistry with Endodontics, Faculty of Dentistry with Clinics, University of Sarajevo, Bosnia and Herzegovina.
Department of Prosthodontics, Faculty of Dentistry with Clinics, University of Sarajevo, Bosnia and Herzegovina.
Acta Med Acad. 2021 Dec;50(3):397-405. doi: 10.5644/ama2006-124.361.
To test the influence of a bleaching procedure using 16% carbamide peroxide (CP) on the colour of composite materials and their consecutive subjection to discolouration in beverages.
Nanocomposite Z550 (3M ESPE) and the microhybrid Z250 (3M ESPE) composite materials were selected for the research. 16% CP was applied to composite plates (15 samples each material) for seven hours a day for 14 days simulating at-home nightguard vital bleaching. The test samples were then divided randomly into three sub-groups and submerged in instant coffee, green tea and Coca Cola for 30 days. The control group (N=5) samples were kept in deionized water. Determination of the Lab* dimensions of colour of the polymerized discs was performed by calibrated spectrophotometer 24 hours later, after the bleaching procedure, and on days 7, 15 and 30 after immersion in the beverages.
After application of 16% CP, there were perceptible changes in the colour of both test materials, which did not exceed the boundaries of acceptability (ΔE<3.48). Coca-Cola did not cause discolouration of the tested composites, but coffee and tea changed their colour above the level of perceptibility already seven days after immersion. A statistically significant difference in the change in colour was established between the materials when they were immersed in coffee (P<0.05).
16% CP does not affect the basic colour of the composites. Immersion in a beverage led to an unacceptable change in the colour of both test materials in coffee and tea, primarily towards black. The greatest discolouration after bleaching was shown by Z550 when immersed in coffee.
测试使用 16%过氧化脲（CP）进行漂白程序对复合材料颜色的影响及其随后在饮料中变色的情况。
选择纳米复合 Z550（3M ESPE）和微混合 Z250（3M ESPE）复合材料进行研究。将 16% CP 应用于复合材料板（每种材料 15 个样本），每天持续 7 小时，共 14 天，模拟家庭夜间使用牙托美白。然后将测试样本随机分为三组，分别在速溶咖啡、绿茶和可口可乐中浸泡 30 天。对照组（N=5）样本保存在去离子水中。在漂白程序后 24 小时以及浸泡在饮料后 7、15 和 30 天，使用经过校准的分光光度计测定聚合盘的 Lab*颜色维度。
应用 16% CP 后，两种测试材料的颜色都发生了明显变化，但未超出可接受范围（ΔE<3.48）。可口可乐未导致测试复合材料变色，但咖啡和茶在浸泡 7 天后改变了颜色，已经超过了可察觉水平。当材料浸泡在咖啡中时，发现颜色变化在材料之间存在统计学上的显著差异（P<0.05）。
16% CP 不会影响复合材料的基本颜色。浸泡在饮料中会导致两种测试材料在咖啡和茶中的颜色发生不可接受的变化，主要是向黑色变化。在咖啡中浸泡后，Z550 的漂白后变色最大。
