Background. Use of higher peroxide concentrations for professional at-home vital bleaching often balances two factors in patient compliance: whitening and tolerability. Development of a polyethylene strip coated with a very thin (0.10-millimeter) layer of 14 percent hydrogen peroxide gel (Crest Whitestrips Supreme, Procter & Gamble, Cincinnati)—which represents an increase in concentration and a decrease in amount of gel—was believed to allow for greater at-home whitening with little additional oral soft-tissue exposure to peroxide.
Methods. The authors conducted a randomized, double-blind, two-week clinical trial with 38 adults to evaluate the safety and efficacy of twice-daily use of the thin, concentrated bleaching gel strip versus the effects of a control product (Crest Whitestrips, Procter & Gamble). The two products differed only in concentration (14 percent versus 6 percent) and gel layer thickness (0.10 mm versus 0.20 mm). The authors measured efficacy from digital images using the Commission Internationale de l’Eclairage L*a*b* color scale. They assessed safety via subject interviews and clinical examination and compared treatments using analysis of covariance.
Results. Relative to baseline color, both strip groups exhibited significant (P < .001) improvement in yellowness, brightness and composite color change. Between-group comparisons after two weeks demonstrated significant (P < .003) color improvement for the experimental strip relative to the control. Both products were well-tolerated generally. Despite the concentration differences, clinical examination of each group showed a similar low level (11 percent) of "minor oral irritation."
Conclusion. Use of the thin 14 percent hydrogen peroxide gel strip resulted in greater whitening, including 42 to 49 percent greater improvement in tooth color and faster whitening onset than that seen with a 6 percent hydrogen peroxide whitening strip, without clinical evidence of increased oral-tissue irritation.
Clinical Implications. Use of whitening strips with a thin, concentrated layer of hydrogen peroxide gel may represent a useful approach for professionally directed at-home vital bleaching.
