Whitening Efficacy and Color Degradation Profile of 2-Hour Whitening Strips

Objectives: ,  This study evaluated safety, whitening efficacy and post-use color degradation profile of 2-hour whitening strips relative to placebo. Methods: , This was a randomized, double-blinded, parallel design clinical study.  Thirty-nine adult volunteers with no history of prior bleaching, no existing tooth sensitivity and the Vita shade of A2 or darker on maxillary anterior teeth were enrolled and randomized to treatment.  Subjects were randomized to one of two treatments:  1) 10% hydrogen peroxide high adhesion whitening strip (Crest 3-D White Express) and 2) a placebo strip. Each treatment was worn for 2 hours daily for 4 days.  Subjects used regular cavity protection toothpaste and regular manual brush throughout the study.  Efficacy (digital image analysis) and safety (oral exams and subject interviews) were assessed at Baseline, Day 5 (end-of-treatment), 6 Weeks post-treatment and 3 Months post-treatment. Results: , Mean age was 30 and 64% of subjects were female.  At each study visit, the 2-hour strip group demonstrated significant (p < 0.0001) improvement of b* and L* tooth color parameters relative to placebo.  The end-of-treatment (Day 5) adjusted mean change from placebo was -2.16 for Δb* and 1.70 for ΔL*.  The improvement in tooth color remained stable for three months post-treatment with Month 3 adjusted mean change from placebo of -1.94 for Δb* and 1.44 for ΔL*.  Tooth sensitivity and oral irritation were the most common adverse events in the study. Conclusions: , The study demonstrated a visible whitening effect from the use of four 10% hydrogen peroxide, 2-hour Whitening strip. The post-whitening tooth color was maintained for 3 month post-treatment.