Daytime use of a custom bleaching tray or whitening strips: initial and sustained color improvement

To compare the clinical response of 6% hydrogen peroxide whitening strips and a 10% carbamide peroxide custom tray system under common daytime usage conditions, in an Italian dental research center.

Informed consent and baseline measurements were collected, and 43 healthy adults were randomly assigned to 6% hydrogen peroxide whitening strips (Crest Whitestrips) or the 10% carbamide peroxide custom tray (Opalescence 10%). The maxillary arch was treated twice daily for 30 minutes at-home. Treatment was discontinued after 2 weeks, and subjects were monitored for an additional 4 weeks. Efficacy (initial and sustained) was measured objectively from standard digital images of the maxillary facial tooth surfaces using the international CIELAB system. Safety was assessed from interview and examination. Treatments were compared after 2 weeks (end-of-treatment) and 6 weeks (4 weeks post-treatment) using analysis of covariance methods.

Both groups exhibited color improvement at the Week 2 end-of-treatment visit. For yellowness, mean (SD) Deltab* at Week 2 was -2.10 (0.70) for the strip group and -1.61 (1.03) for the tray group. For lightness, mean (SD) DeltaL* at Week 2 was 1.25 (0.92) for the strip group and 1.17 (1.19) for the tray group. Compared to Week 2, the strip group retained 89-92% of the initial Deltab* and DeltaL* color improvement at Week 6 (4 weeks post-treatment), while the tray group had 80-90%. Groups differed significantly (P< 0.05) on end-of-treatment and post-treatment Deltab*, favoring the strips. Both daytime treatments were well-tolerated, with minor tooth sensitivity and oral irritation representing the most common findings.