Comparative response of whitening strips to a low peroxide and potassium nitrate bleaching gel

To evaluate the clinical response of a low peroxide concentration bleaching system with a desensitizing agent relative to a marketed control.

After balancing for baseline color and age, 34 healthy adult volunteers were randomized to one of two marketed bleaching systems, 5% carbamide peroxide bleaching gel + potassium nitrate in a custom tray (Colgate Platinum Gentle Plus) or 6.0% hydrogen peroxide bleaching strips (Crest Whitestrips). Daily contact time was 6-8 hours for the tray system compared to 1 hour for the strip system, following manufacturers' instructions. Whitening was measured objectively using digital image analysis to assess L*a*b* after 7 days, while tolerability was assessed through interview and examination.

The predominantly female (85%) and non-smoking (91%) study population ranged from 20-47 years of age. Both treatments yielded a statistically significant (P < 0.001) whitening benefit with respect to reduction in yellowness (Ab*) and improvements in other color endpoints (deltaL*, deltaE*, and a new parameter, deltaW*) compared to baseline. The strip group experienced greater color improvement on average for all color parameters in the study. After 7 days treatment, the adjusted mean deltab* was -1.24 in the strip group and -0.65 in the tray group, with these groups differing significantly (P = 0.04). Tooth sensitivity was reported by 13% of subjects using the hydrogen peroxide strips, compared to 22% of subjects using the carbamiide peroxide potassium nitrate tray system. No subjects discontinued treatment early due to an adverse event.