Clinical comparison of whitening with 6.0% and 5.3% hydrogen peroxide whitening strips

Objective: This research was conducted to compare the clinical response of two different peroxide-containing gel formulations delivered using self-applied whitening strips. Methods: A meta-analysis was conducted to assess the effectiveness of two different whitening gel formulations: a low water 5.3% hydrogen peroxide gel and a high water 6.0% hydrogen peroxide gel. Both studies were randomized, double blind trials. The maxillary teeth were treated twice daily over a 2-week period with whitening strips. Efficacy (L*a*b* color change) was measured objectively by digital image analysis. Results: A total of 60 adults ranging from 19-85 years of age participated in the research. Both treatments were effective in whitening teeth, as evidenced by a statistically significant improvement from baseline (p < 0.05). After adjusting for study effects and baseline, mean Db* (SE) for the high water content 6.0% hydrogen peroxide gel strip was –1.85 (0.151) compared to –1.41 (0.164) for the low water content 5.3% strip, with these treatments differing significantly (p=0.023). For the primary response variable Db*, this represented a 31.4% improvement in whitening for the higher water/higher concentration gel compared to the lower water/lower concentration gel. Outcomes for the other color parameters favored the 6.0% formulation. Both treatments were well-tolerated, and no subjects discontinued treatment due to adverse events related to bleaching. Conclusion: For whitening strips, this research demonstrates that a high water 6.0% hydrogen peroxide gel provides superior whitening clinical response compared to a low water 5.3% hydrogen peroxide formula.