Method: This was a randomized, double-blinded, parallel design clinical study. Fifty six adult volunteers with no history of prior bleaching, no existing tooth sensitivity and the Vita shade of A2 or darker on maxillary anterior teeth completed the study. Subjects were randomized to one of the two treatments: 1) 10% hydrogen peroxide high adhesion whitening strip (Crest 3-D White 1-Hour Express) used with a regular cavity protection toothpaste and a flat trim manual brush and 2) a regular cavity protection toothpaste and a flat trim manual brush as a negative control. The strip was worn 1 hour daily for 4 days. Efficacy (digital image analysis) and safety (oral exams and subject interviews) were assessed at Baseline, Day 2 (after 1 day of treatment) and Day 5 (after 4 days of treatment).
Result: Mean age was 36 and 66% of subjects were female. At each study visit, the 1-hour strip group demonstrated significant (p < 0.02) improvement of b* and L* tooth color parameters relative to Baseline and the negative control. For the strip group, the Day 2 adjusted mean yellowness reduction (Δb*) was -0.54 and the adjusted mean lightness improvement (ΔL*) was 0.52. The benefit continued to increase through end-of-treatment (Day 5) with Day 5 adjusted mean Δb* and ΔL* values of -1.58 and 1.36, respectively. Both treatments were well-tolerated. Mild, transient tooth sensitivity and oral irritation were the two types of adverse events reported in the study. No subject discontinued treatment due to an adverse event.
Conclusion: The study demonstrated an immediate whitening effect from use of a single 10% hydrogen peroxide, 1-hour Whitening strip, and the benefit continued to improve through the course of the study.