Purpose: To assess the whitening efficacy of a new whitening power toothbrush, designed specifically for the removal of extrinsic stains, relative to an 8.7% hydrogen peroxide paint-on gel control. Methods: This study was a randomized, single center, two-treatment, parallel design, 4-week, controlled study (n=27) conducted to measure the whitening ability of an experimental power toothbrush relative to a peroxide paint-on gel control used in conjunction with a manual toothbrush. Subjects were randomized to the experimental battery-powered toothbrush group (twice a day brushing with Crest Cavity Protection dentifrice for 2 minutes each time) or the peroxide paint-on gel control group who applied Colgate Simply White Night per manufacturer's instructions once a day prior to bedtime for the first 14 days of the study as well as brushed twice a day with Crest Cavity Protection dentifrice for 2 minutes using the ADA manual reference toothbrush over the 4-week study period. Study evaluations included objective digital image analysis (L* a* b*) and oral soft tissue examinations at baseline, Week 2 and Week 4. In addition, a pilot, single center, 1-week study (n=9) was conducted to measure the absolute whitening ability of the experimental power toothbrush as measured by digital imaging analysis in a high stain population, induced by I week of rinsing with tea. Study evaluations included digital image analysis (L*a*b*) and oral soft tissue examinations at baseline and Week 1 following brushing with the experimental power toothbrush. Results: In the comparative study, the average baseline L*, b*, and W* values were well-balanced across treatment groups. At the Week 2 visit, adjusted (via ANCOVA) mean DeltaL*, Deltaa*, Deltab* and DeltaW* values of 0.08, -0.41, -0.08, and -0.28, respectively, were observed in the peroxide paint-on control group, relative to adjusted mean DeltaL*, Deltaa*, Deltab* and DeltaW* values of 0.16, -0.19, -0.38, and -0.33, respectively, in the experimental power toothbrush group. No statistically significant differences were observed between the two treatment groups for any of the endpoints. However, Deltab* and DeltaW* values for the experimental power toothbrush group were statistically significantly improved relative to baseline. At the Week 4 visit, adjusted (via ANCOVA) mean DeltaL*, Deltaa*, Deltab* and DeltaW* values of -0.15, -0.24, -0.14, and -0.04, respectively, were observed in the peroxide paint-on control group, relative to adjusted mean DeltaL*, Deltaa*, Deltab* and DeltaW* values of 0.02, -0.12, -0.22, and -0.15, respectively, in the experimental power toothbrush group. No statistically significant differences were observed between the two treatments groups for any color endpoints of DeltaL*, Deltaa*, Deltab*, or DeltaW*. In the induced stain study, the average baseline L*, a*, b*, and W* values were 71.21, 8.28, 19.01, and 35.52, respectively. At the Week 1 visit, the mean DeltaL*, Deltaa*, Deltab*, and DeltaW* values were 0.55, -0.27, 0.00, and -0.51 respectively. The DeltaL* and DeltaW* were statistically significantly improved (P < 0.05) relative to baseline.