Department of Operative Dentistry, School of Dentistry, University of Athens, 2 Thivon Str., Goudi, Athens, Greece.
J Dent. 2010;38 Suppl 2:e129-36. doi: 10.1016/j.jdent.2010.06.006. Epub 2010 Jun 25.
The purpose of the study was to evaluate gloss and color changes of resin composites after exposure to different bleaching agents.
Products used, were: Nite White ACP (10% carbamide peroxide gel), Crest Classic and Supreme Whitestrip (6.5% and 14% hydrogen peroxide strips, accordingly). A hybrid (Herculite XRV) and a nanohybrid (Premise) resin composite were exposed to the bleaching agents. Twenty-four disk-shaped specimens per composite were subjected to bleaching by each of the agents (n=8) for up to 2 weeks. Color changes using CIE-Lab* system (50:50% acceptability threshold: ΔE*=3.3) were recorded after 1 and 2 weeks bleaching cycles relative to baseline measurements. In addition, gloss measurements (in gloss units) were performed at the same bleaching intervals and gloss changes were calculated.
All bleaching agents tested provided decrease in gloss of both composites after 2-week bleaching (p<0.05). No differences were detected among the three bleaching regimens, for up to 2-week application, in terms of color and gloss changes on both composites. After the 2-week bleaching period, hybrid composite presented higher gloss reduction (%) than nanohybrid regardless of the bleaching agent (p<0.05). Color change (ΔE*) was lower than 3.3 for all composite-bleaching agent combinations. After 1- and 2-week bleaching time, the nanohybrid composite provided higher color change than the hybrid under all bleaching procedures (p<0.05). No strong correlation was proved between color (ΔE*) and gloss changes caused by bleaching treatments.
After 2-week bleaching cycles, composites showed significant gloss reduction (p<0.05). Color alteration was below the 50:50% acceptability threshold (ΔE*<3.3) and it was product-depended. There was no significant difference in color and gloss changes between the evaluated bleaching strips and 10% carbamide peroxide gel.
本研究旨在评估不同漂白剂处理后树脂复合材料的光泽度和颜色变化。
使用的产品有：Nite White ACP（10%过氧化脲凝胶）、Crest Classic 和 Supreme Whitestrip（分别为 6.5%和 14%过氧化氢条）。将一种混合树脂复合材料（Herculite XRV）和一种纳米复合树脂复合材料暴露于漂白剂中。每种试剂（n=8）对 24 个圆盘状样本进行漂白处理，持续 2 周。与基线测量相比，在 1 周和 2 周漂白周期后使用 CIE-Lab系统（50:50%可接受性阈值：ΔE=3.3）记录颜色变化。此外，在相同的漂白间隔测量光泽度（以光泽度单位表示），并计算光泽度变化。
所有测试的漂白剂在 2 周漂白后都降低了两种复合材料的光泽度（p<0.05）。在长达 2 周的应用中，三种漂白方案之间在两种复合材料的颜色和光泽度变化方面均无差异。在 2 周的漂白期后，混合复合材料的光泽度降低率（%）高于纳米复合材料，无论使用哪种漂白剂（p<0.05）。所有复合材料-漂白剂组合的颜色变化（ΔE*）均低于 3.3。在 1 周和 2 周的漂白时间后，在所有漂白程序下，纳米复合材料的颜色变化均高于混合复合材料（p<0.05）。在漂白处理引起的颜色（ΔE*）和光泽度变化之间没有证明存在强相关性。
在 2 周的漂白周期后，复合材料的光泽度明显降低（p<0.05）。颜色变化低于 50:50%的可接受性阈值（ΔE*<3.3），且取决于产品。评估的漂白条和 10%过氧化脲凝胶之间在颜色和光泽度变化方面没有显著差异。
