Department of Operative Dentistry, Federal University of Paraíba, João Pessoa, PB, Brazil.
J Dent. 2010 Dec;38(12):956-63. doi: 10.1016/j.jdent.2010.08.003. Epub 2010 Aug 13.
This double-blind randomized clinical trial aimed to evaluate the whitening effect of two at-home tooth bleaching agents and the effect of dietary habits after 2 years. The patients' view about bleaching longevity was also investigated.
Ninety-two subjects with mean shade of C1 or darker for the six maxillary anterior teeth were randomized into two groups (n=46) according to the carbamide peroxide (CP) concentration: 10% (CP10) or 16% (CP16). The treatment was performed using the whitening agent in a tray for 2h/day during 3 weeks. Shade evaluations were done with a shade guide and a spectrophotometer at baseline, 1-month, 6-month, 1-year and 2-year post-bleaching.
Eighty-one (88%) of the original 92 subjects enrolled in the study were recalled at 2-year follow-up and, the tooth shade remained significantly lighter than at baseline, in both treatment groups, considering the tooth shade median values (p<0.001) or the color parameters: La (p<0.001) for CP10 and, Lb for CP16 group (p<0.001). Subjects from CP10 and CP16 reported a consumption of beverage and food stains as high as at 6-month and 1-year recalls and, more than 66% of the participants from each group reported a tooth shade relapse from mild to moderate (p=0.6).
At 2-year post-bleaching, tooth shade remained lighter than at baseline for both CP concentrations tested. Tooth shade relapse associated to increasing of a* and b* color parameters were observed for both groups when compared to the end of the treatment (CEP # 37/05).
本双盲随机临床试验旨在评估两种家庭用牙齿漂白剂的美白效果以及两年后饮食习惯的影响。还调查了患者对漂白持久度的看法。
92 名上颌前六颗牙齿平均比 C1 或更暗的患者根据过氧脲（CP）浓度随机分为两组（n=46）：10%（CP10）或 16%（CP16）。治疗时，使用托盘中的漂白剂每天 2 小时，持续 3 周。在基线、1 个月、6 个月、1 年和 2 年漂白后，使用比色板和分光光度计进行颜色评估。
81 名（88%）原始 92 名受试者在 2 年随访时被召回，考虑到牙齿颜色中位数值（p<0.001）或颜色参数：La（p<0.001）对于 CP10 和 CP16 组的 Lb（p<0.001），两组的牙齿颜色均明显比基线时更浅。CP10 和 CP16 的受试者报告说，在 6 个月和 1 年的随访中，饮料和食物污渍的消耗量高达最高水平，而且每组超过 66%的参与者报告说牙齿颜色从轻度到中度复发（p=0.6）。
在 2 年漂白后，与基线相比，两种 CP 浓度的牙齿颜色都保持更浅。与治疗结束时相比（CEP#37/05），两组的 a和 b颜色参数增加，观察到牙齿颜色复发。
