Clinical Efficacy of Two Direct-to-Consumer Whitening Strips

Objective: This clinical study compared efficacy of two direct-to-consumer whitening strips. Methods: 57 subjects were randomized to one of two whitening regimens: Oral-B® Rembrandt® Whitening Strips Premium worn once a day for 7 days (7-day strips) or Crest® Whitestrips® Premium Plus containing 10% hydrogen peroxide and worn twice a day for 10 days (10-day strips). Treatment followed the manufacturers written instructions which included 30 minutes wear time per strip application. Tolerability was assessed from subject interviews and oral examination, and efficacy was measured objectively from CIELAB digital measurements. Whitening response was compared at Day 6, Day 8 and at the end-of-treatment (Day 8 for the 7-day strip and Day 11 for the 10-day Strip) using the analysis of covariance method. Results: The study population consisted of healthy adults averaging 30.3 years of age. At each study visit, the 10-day strip group demonstrated significantly greater improvement of b* and L* (p £ 0.0051) relative to the 7-day strip group. At the end-of-treatment, use of 7-day strips resulted in adjusted means of -1.19 for Db* and 1.30 for DL*, while the use of 10-day strips resulted in adjusted means of -2.32 for Db* and 2.23 for DL*. The 10-day strip group demonstrated significantly greater (p < 0.0001) tooth color improvement (both Db* and DL*) relative to the 7-day strip group at end-of-treatment. Both treatments were generally well-tolerated. Conclusion: Use of a direct-to-consumer 10% hydrogen peroxide, 10-day whitening strip resulted in a significantly greater tooth whitening response relative to that of a 7-day marketed strip.