Use of a physical barrier to improve efficacy of a paint-on whitening gel: a seven-day randomized clinical trial

J Clin Dent. 2006;17(5):117-21.


Objective: This randomized, examiner-blind clinical trial evaluated the impact of a physical barrier on tooth whitening response of a peroxide-containing paint-on gel.

Methodology: A total of 33 adult volunteers, ranging from 18-75 years of age, were randomized to one of two treatment groups: a whitening paint-on gel used alone, or a whitening paint-on gel applied to the tooth surface and immediately covered with a polyethylene strip barrier. Both treatments were used twice a day for seven days, and all subjects used a cavity protection dentifrice and an extra-soft toothbrush twice a day while in the study. Whitening efficacy was assessed using L*a*b* color analysis obtained via digital imaging. Efficacy and safety data were collected at baseline and again at Days 2, 5, and 8.

Results: Use of a whitening gel with a protective barrier resulted in significant (p < or = 0.025) color improvement from baseline (as evident by mean deltab* and deltaL*) at Days 5 and 8, while changes from baseline were not significant for the group using whitening gel alone for the same time points. At Day 2, subjects in the barrier group had a significant (p = 0.046) yellowness reduction (deltab*) relative to baseline. Between-treatment comparisons were significant for deltab* at Days 5 and 8 (p < or = 0.015) and for deltab* whitening improvement slopes for the duration of the study (p < 0.002). Both treatments were well tolerated, and no subjects discontinued treatment due to an adverse event.

Conclusion: Protecting hydrogen peroxide in the whitening gel from the oral environment with a polyethylene barrier increases the magnitude of the whitening response for a paint-on gel, with results evident as early as after five days of product use.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Analysis of Variance
  • Carbamide Peroxide
  • Colorimetry
  • Complex Mixtures / administration & dosage
  • Drug Combinations
  • Female
  • Humans
  • Male
  • Middle Aged
  • Oxidants / administration & dosage*
  • Peroxides / administration & dosage*
  • Single-Blind Method
  • Tooth Bleaching / instrumentation
  • Tooth Bleaching / methods*
  • Urea / administration & dosage
  • Urea / analogs & derivatives*


  • Colgate Simply White Clear Whitening Gel
  • Complex Mixtures
  • Drug Combinations
  • Oxidants
  • Peroxides
  • Carbamide Peroxide
  • Urea