Randomized clinical trial comparing whitening strips, paint-on gel and negative control.

PURPOSE: To evaluate efficacy and safety of peroxide-containing whitening strips and a paint-on gel relative to a non-peroxide experimental control. METHODS: After informed consent, 52 healthy adults in Shanghai, China were randomized to one of three treatment groups: 6% hydrogen peroxide whitening strips (Crest Whitestrips), 5.9% hydrogen peroxide paint-on gel (Colgate Simply White), or water rinse which served as a negative experimental control. Strip use was twice daily over 7 days, while the paint-on gel and rinse were used twice daily over 14 days. Efficacy was measured from standard digital images of the maxillary anterior teeth, and safety was assessed from interview and intraoral examination. RESULTS: Whitening strips provided the greatest end-of-treatment reduction in yellowness (Deltab*), with adjusted means +/- standard errors of -1.72 +/- 0.18 for the strip group, -0.48 +/- 0.10 for the paint-on gel group, and 0.13 +/- 0.09 for the water rinse group. For DeltaL* (lightness), end-of-treatment adjusted means +/- standard errors were 1.88 +/- 0.21 for the strip group, 0.60 +/- 0.15 for the paint-on gel, and -0.10 +/- 0.18 for the negative control. Groups differed significantly (P< 0.007) with respect to Deltab* and DeltaL* at end-of-treatment, as well as other color parameters. All treatments were well-tolerated.