Effect of Marketed Whitening Dentifrice on Intrinsic Tooth Color

Objectives: The primary objective of this study was to evaluate the whitening efficacy of a marketed whitening toothpaste with hydrogen peroxide on intrinsic tooth color relative to a negative control.
Methods: After IRB review, informed consent was obtained from the target population of 47 adult subjects that have never whitened their teeth and had a Vita Shade of A2 or darker on the facial surfaces of the anterior teeth. After a dental prophylaxis subjects were randomized to either a conventional NaF/silica (negative control) or Colgate® Optic White Radiant™ Toothpaste (test). Subjects used the assigned products per the manufacturer’s instructions. Whitening efficacy and oral safety were obtained at Baseline, Week 1, Week 4 and Week 6 by digital image analysis, oral examination and status interview.
Results: Mean (SD) age was 51.7 (9.33) and 70% were female. The test dentifrice group did not show a significant (p=0.187) change in yellowness (Δb*) compared to baseline at Week 1, and demonstrated a significant (p≤0.013) increase in b* at Week 4 and 6. In addition, the test dentifrice group had a statistically significant (p=0.01) decrease in lightness (ΔL*) at Week 1 relative to baseline. At all time points the test dentifrice group was not significantly different from the negative control (p > 0.05) in either yellowness (b*) or lightness (L*). The adjusted mean Δb* values were 0.147 and 0.04 at Week 1, 0.343 and 0.211 at Week 4, and 0.431 and 0.388 at Week 6 for test and control groups, respectively. The adjusted mean ΔL* values were -0.35 and -0.58 at Week 1, -0.125 and -0.512 at Week 4, and -0.132 and -0.397 at Week 6 for test and control groups, respectively.
Conclusions: Use of tested marketed whitening toothpaste with hydrogen peroxide did not result in significant tooth color improvement relative to baseline or to negative control.