Objective:  A randomized, double-blind clinical trial was conducted to evaluate the clinical effectiveness and tolerability of 6% hydrogen peroxide whitening strips relative to placebo. 

Methods: 30 healthy adults with no history of vital bleaching or hypersensitivity were randomized to Crestâ Whitestrips® (6% hydrogen peroxide) or placebo.  Maxillary teeth were treated unsupervised twice daily for 30 minutes over a 14-day period, and clinical response was measured from digital images (CIELAB), examination and interview at baseline and end-of-treatment. 

Results: The study population ranged from 22-56 years, 63% were female, and 17% used tobacco.  Groups were well-balanced (p > 0.46) on pertinent demographic and behavioral characteristics and starting L*a*b* tooth color.  Relative to baseline, the 6% strip group experienced significant (p < 0.0001) reduction in yellowness (Db*) and increased brightness (DL*) with treatment, with Day 15 means (SD) of –1.8 (0.51) and 1.4 (0.80) for Db* and DL*, respectively.  All (100%) subjects in the 6% strip group had measured two parameter (b* & L*) color improvement.  There was no evidence of a significant (p > 0.18) placebo response, with the 6% strip differing significantly from placebo (p < 0.0001) for Db* and DL*.  Minor tooth sensitivity was the most common adverse event, reported by 20% of subjects in the 6% strip group and 0% in placebo.  No subjects discontinued strip use early because of a treatment-related adverse event.

Conclusion: In this double blind, placebo-controlled clinical trial, twice daily use of a 6% hydrogen peroxide strip yielded significant tooth whitening without meaningful side effects.