Clinical trial of long-term color stability of hydrogen peroxide strips and sodium percarbonate film

Abstract

Purpose: To compare initial and sustained clinical response of 6% hydrogen peroxide whitening strips and a 19% sodium percarbonate film in a randomized controlled trial.

Methods: Informed consent was obtained, after which 72 subjects were randomized to 6% hydrogen peroxide whitening strips (Crest Whitestrips), 19% sodium percarbonate brush-applied gel that dries as a film (Crest Night Effects), or placebo brush-applied gel without peroxide. Efficacy (digital imaging) and safety (clinical examination and interview) were assessed after 2 weeks treatment, and again at up to eight post-treatment timepoints over an 18-month post-treatment period.

Results: For Deltab* (yellowness), end-of-treatment adjusted means +/- standard errors (SE) were -2.37 +/- 0.088 for the strip group, -1.36 +/- 0.091 for the film group, and -0.08 +/- 0.090 for the placebo group. For DeltaL* (brightness), end-of-treatment adjusted means +/- SE were 2.40 +/- 0.121 for the strip group, 1.47 +/- 0.125 for the film group, and 0.06 +/- 0.122 for the placebo group. Groups differed significantly (P< 0.02) at end-of-treatment and throughout post-treatment. All treatments were well-tolerated, both peroxide-containing systems exhibited appreciable color retention throughout the 18-month post-treatment period, and there were no meaningful, persistent adverse events seen with long-term follow-up.