Purpose: To evaluate the clinical response of a professional whitening strip system used by a university-based population residing in Mexico City, Mexico.
Methods: A randomized, double-blind, placebo-controlled study was conducted to evaluate the safety and efficacy of 6.5% hydrogen peroxide whitening strips used over a 3-week period. A total of 30 volunteer students and staff at the National Autonomous University of México (Mexico City) were randomly assigned to the peroxide or placebo strip groups. Strips were worn for 30 minutes two times a day for 3 weeks. Efficacy was evaluated using digital image analysis to assess change in L* a* b* tooth color, while safety was assessed by oral examination and subject interview.
Results: Relative to placebo, the 6.5% hydrogen peroxide strip group experienced nearly a 4-unit color improvement (Deltab*). Treatment groups differed significantly (P< 0.0001) with respect to yellowness (Deltab*), lightness (DeltaL*) and redness (Deltaa*). Adjusted mean (SE) overall color improvement (DeltaW*) was -4.76 (0.27) for the peroxide strips, compared to the near zero, -0.21 (0.28) for the placebo control. Strip use was well tolerated. Minor, transient tooth sensitivity occurred more frequently in the peroxide group, and overall, no subjects modified or discontinued treatment early because of adverse events.