Meireles Sônia Saeger, dos Santos Iná da Silva, Della Bona Alvaro, Demarco Flávio Fernando
Department of Operative Dentistry, Federal University of Paraíba, João Pessoa, Paraíba, Brazil.
J Am Dent Assoc. 2009 Sep;140(9):1109-17. doi: 10.14219/jada.archive.2009.0337.
The use of high-concentration tooth-bleaching agents has been associated with increased longevity of the whitening effect. The authors conducted a randomized controlled clinical trial to evaluate the longevity of the whitening effect at one year of two at-home tooth-bleaching agents.
The authors randomly assigned 92 participants with a mean shade of C1 or darker for six maxillary anterior teeth into two equal-sized groups according to carbamide peroxide concentration: 10 percent (CP10) or 16 percent (CP16). Treatment involved the use of a whitening agent in a tray for two hours daily for three weeks. The authors evaluated tooth shade with a shade guide and a spectrophotometer at baseline and one week, six months and one year after bleaching. Participants in both groups answered questions about their dietary and oral hygiene behaviors.
At the one-year recall appointment, the teeth in both groups remained significantly lighter than at baseline. At this time, participants from the CP10 and CP16 groups consumed staining beverages and foods at a level as high as at the six-month recall appointment, and this consumption level was not statistically significant between groups (P > .5).
One year after bleaching, both treatment groups had the same median tooth shade, which remained lighter than at baseline.
Higher carbamide peroxide concentration does not increase the longevity of the whitening effect of at-home tooth-bleaching agents.
高浓度牙齿漂白剂的使用与美白效果的持久度增加有关。作者进行了一项随机对照临床试验，以评估两种家用牙齿漂白剂在一年时美白效果的持久度。
作者将92名上颌前六颗牙齿平均色度为C1或更深的参与者，根据过氧化脲浓度随机分为两个等规模的组：10%（CP10）或16%（CP16）。治疗方法是每天在托盘里使用美白剂两小时，持续三周。作者在基线时以及漂白后一周、六个月和一年时，用比色板和分光光度计评估牙齿色度。两组参与者都回答了有关他们饮食和口腔卫生行为的问题。
在一年的回访预约时，两组牙齿的颜色仍显著比基线时更白。此时，CP10组和CP16组参与者摄入染色饮料和食物的程度与六个月回访预约时一样高，且两组之间的这种摄入程度无统计学差异（P>.5）。
漂白一年后，两个治疗组的牙齿中位色度相同，且仍比基线时更白。
较高的过氧化脲浓度不会增加家用牙齿漂白剂美白效果的持久度。
