Three-month Clinical Trial Comparing Two At-home Whitening Systems Under Common Usage Conditions

Objective: This randomized clinical trial was conducted to compare a professionally-administered, at-home bleaching system to self-directed, at-home whitening strips. Methods: Balancing for baseline color and age, 50 healthy adults were randomized to one of two at-home bleaching systems. Subjects received either 6.0% hydrogen peroxide bleaching strips or a 10% carbamide peroxide bleaching gel and a custom tray. Both systems were used twice daily for 30 minutes over 14 days, after which, subjects were monitored over a 3 month period to assess color retention. Whitening was measured objectively as L*a*b* using digital image analysis. Results: A total of 48 subjects (25 in the strip group and 23 in the tray group) completed the 3-month study. Both treatments yielded a statistically significant (p < 0.0001) whitening benefit as measured using Db*, DL* and DE*. The strip group experienced greater average initial color improvement for all color parameters in the study. At end-of-treatment, adjusted mean DE* was 3.26 in the strip group and 2.33 in the tray group, with these groups differing significantly (p < 0.004). While both groups exhibited favorable color retention, the strip group exhibited significantly (p < 0.03) greater whitening at Week 6 and Month 3 for DE*, as well as Db* and DL*. Except for one subject in the tray group who discontinued treatment prior to Day 14 because of discomfort, both treatments were generally well tolerated. Conclusion: Under similar usage conditions, the 6.0% hydrogen peroxide whitening strip system resulted in greater initial whitening and superior color retention compared to a 10% carbamide peroxide tray system. (The research was supported by The Procter & Gamble Co.)