Clinical Comparison of Two At-home Bleaching Systems Having Different Peroxide Delivery

Objective: The aim of the study was to evaluate the efficacy and safety of three modifications of an experimental paint-on bleaching film, containing 19% sodium percarbonate (equivalent to 5.3% hydrogen peroxide) versus a flexible polyethylene strip coated with a 6% hydrogen peroxide gel (Whitestrips). Methods: A total of 99 patients (aged 18-48) were randomised to one of 5 treatments in what was a parallel leg, partially blinded, placebo controlled, single centre study of 2 weeks duration. Prior to product assignment half the subjects in each leg received a dental prophylaxis. Bleaching agents were self-applied to the facial surfaces of the anterior teeth and left overnight (experimental bleaching film) or applied twice daily for 30 min (Whitestrips). Efficacy and safety measurements at baseline, 7 and 14 days comprised of oral soft tissue examinations and digital image analysis (DIA). Whitening efficacy was determined by evaluating changes from baseline in tooth yellowness (delta b*) and tooth brightness (delta L*). Statistical analysis was by ANCOVA. Results: Both the experimental bleaching films and positive control showed a significant reduction (p<0.001) in tooth yellowness after 14 days usage giving a delta b* of -0.83 to °V1.23 (depending on modification) and -1.90 respectively. Similarly the test products showed significant increase in levels of tooth brightness after 14 days usage, giving a delta L* range of 0.76-1.14 for patients using the three modifications of experimental bleaching film and 1.69 for patients using Whitestrips. The placebo group showed a significantly lower overall tooth colour change (p<0.001) from baseline than all other groups (delta L*=0.13 and delta b* 0.13 at day 14). Conclusions: The research concluded that the experimental bleaching formulations provided a significant and measurable tooth whitening effect, lower than but comparable to that of Whitestrips. Supported by Procter & Gamble.