Tooth Whitening Efficacy of Colgate Visible White Compared to Opalescence

Objectives: The purpose of this 14-day parallel, double blind clinical study was to compare the tooth whitening efficacy of two custom tray-delivered bleaching products: Colgate Visible White (9% hydrogen peroxide) and Opalescence (20% carbamide peroxide). Methods: Forty-six adults were assigned to use Colgate Visible White or Opalescence following a random list and balanced based on baseline tooth shade scores. Consenting participants had 6 unrestored maxillary anterior teeth averaging a shade ranking score of 9 (A3) in the Vitapan Classical Shade Guide scale of 1 through 16 (lightest to darkest) established by H Rauter GmbJ & Co; Bad Säckingen, Germany. Participants followed at-home 30-minute daily applications of the assigned product after brushing with a non-bleaching dentifrice (Colgate Great Regular Flavor). One of two calibrated examiners performed the baseline, 5-day, 7-day, and 14-day tooth shade evaluations for a given participant, utilizing the same Vita guide under unmodified color-corrected lighting conditions. Forty-two participants made all visits. Only one participant from each group discontinued treatment early due to mild discomfort. Bleaching efficacy was measured with respect to mean shift (reduction from baseline) in rank scores of the maxillary anterior teeth, in which baseline rank scores functioned as covariables. The level of significance was set at p=0.05 for analyses of covariance (ANCOVA) and post-ancova pairwise t-tests comparison of groups. Results: Between-group comparison showed no significant mean baseline score difference. Both groups exhibited statistically significant mean shade rank score improvements from baseline after 5,7, and 14 days at 3.12-to-3.69-to-4.6 for Colgate Visible White and 1.68-to-2.32-to-3.8 for Opalescence. Conclusion: Between-group comparisons show that while Colgate Visible White (9% hydrogen peroxide) provides a statistically significant tooth whitening improvement over Opalescence (20% carbamide peroxide) after 5 and 7 days, both products have a similar whitening effect after two weeks of use. Supported by Colgate Palmolive Co and PHS/NIH: 1R25RR17589.