Purpose: To compare tooth whitening with 6% hydrogen peroxide whitening strips and two whitening dentifrices in a 12-week randomized controlled trial at a Belgian dental school.
Methods: After informed consent, 46 healthy adults were randomly assigned to one of three strip + dentifrice treatment groups. Subjects received either 6% hydrogen peroxide whitening strips (Crest Whitestrips) and an anticavity toothpaste (Crest Cavity Protection), placebo strips and a sodium fluoride (NaF) whitening dentifrice (Mentadent Whitening Toothpaste) or placebo strips and a sodium monofluorophosphate (MFP) whitening dentifrice (Rembrandt Low Abrasion Whitening Toothpaste). Strip use (peroxide or placebo) was for 30 minutes, twice daily for 2 weeks, while dentifrice use was at least twice daily for 12 weeks. Efficacy was measured from standardized digital images of the maxillary facial tooth surfaces, while safety was evaluated from oral examination and interview. Treatments were compared after 2 weeks (strip use) and 12 weeks (dentifrice use) using analysis of covariance.
Results: All subjects completed the 12-week evaluation. Adjusting for baseline and age, the peroxide strip group had -2.45 Deltab*, 2.39 DeltaL*, and -0.96 Deltaa* at Week 2. Between-group comparisons demonstrated significant (P< 0.0001) reductions in yellowness and redness, and increased brightness favoring the peroxide strip group. The peroxide strip group demonstrated 95%+ color retention (Deltab* & DeltaL*) at Week 12, differing significantly (P< 0.0001) versus either of the continuously used whitening dentifrices. There were no significant (P> 0.18) differences between the whitening dentifrice groups at any timepoints. All treatments were well-tolerated, with minor tooth sensitivity and oral irritation representing the most common findings.