Taken from the IADR www site, 10 March 2005 Baltimore Convention Center 327

Authors - G. KUGEL, S. FERREIRA, S. SHARMA, M.L. BARKER, and R.W. GERLACH,

Objective: This clinical study evaluated a light-enhanced, in-office tooth whitening system, in order to assess whether light enhancement of the peroxide gel affected tooth color and safety. Methods: 33 adults were randomly assigned to one of three treatment groups balancing for age and starting color. Professional treatment involved application of a 25% hydrogen peroxide gel (Discus Dental® Zoom!™) with light enhancement, peroxide gel alone, or the light alone with no peroxide. The 12 anterior teeth were treated 3 times for 20 minutes each. Efficacy was measured objectively as L*a*b* color change using digital images, tooth shade was measured, and safety was evaluated immediately after treatment, and at post-treatment Day 7 and Day 30.

Results: After adjusting for baseline and age, immediate (end-of-treatment) b* (yellowness) were –3.1 (0.25) for the combination group, –2.0∆means (SE) for (0.25) for the gel only group, and –2.4 (0.25) for the light only group. Significant (p < 0.05) color rebound was evident at post-treatment Day 7. By b* were –1.7 (0.20) for the combination group,∆Day 30, adjusted means (SE) for –1.1 (0.20) for the gel only group, and –0.5 (0.20) for the light only group. Both peroxide groups differed significantly (p < 0.05) from light alone on Db* and DL*. Vita shade results were generally similar. Tooth sensitivity represented the most common adverse event in the two gel groups. In the combination group, 91% of subjects experienced tooth sensitivity, the majority of which was moderate or severe. This resulted in 3 subjects discontinuing treatment early during the application visit. Adverse events were low in the light only group.

Conclusion: Use of light enhancement for in-office whitening lead to immediate color change, after which, there was significant color and shade rebound within 7 days, as well as, moderate-to-severe tooth sensitivity during and after treatment.