In-Vitro Whitening Efficacy of Peroxide Dentifrice vs. Silica Whitening Toothpaste

Objective: To evaluate the in vitro efficacy of a new whitening dentifrice containing hydrogen peroxide and abrasive technology as compared to that of a commercial whitening toothpaste containing abrasive technology alone.

Method: Two commercially available whitening toothpastes were evaluated in this study:  Colgate® Optic White^TM containing 1% hydrogen peroxide and calcium pyrophosphate and Crest® 3D White Advanced Vivid containing hydrated silica and sodium hexametaphosphate.  Colgate® Cavity Protection, a regular fluoride dentifrice which does not make a whitening claim, was included as the negative control.  Artificially stained bovine teeth were polished with prophylaxis paste until initial L*, a*, and b* values approached those of human teeth.  The teeth were brushed for two minutes with a dentifrice slurry, rinsed with water, and L*, a*, and b* values were collected with a spectrophotometer.  This process was repeated a total of 14 times to model one week of brushing.  A whiteness index, ΔW* (where W*= ((L*-100)²+a*²+b*²)^1/2), was reported after 14 brushing treatments.  Analysis of variance was used to compare the mean ΔW* value for each product with p<0.05 indicating significant differences between products.  Tukey multiple comparison test was used to make pair-wise comparisons of the products.

Result: :  After 14 treatments, the ΔW* value for the hydrogen peroxide dentifrice was -6.1 + 1.7, the ΔW* value for the silica whitening dentifrice was -3.5 + 1.4, and the ΔW* value for the regular fluoride toothpaste was -0.4 + 0.8.  The ΔW* value for the hydrogen peroxide dentifrice was statistically superior to the ΔW* value for the dentifrice containing silica (p=0.0036).  ΔW* values for the hydrogen peroxide dentifrice and the silica dentifrice were statistically superior to the regular dentifrice (p<0.0001, p=0.0006).    

Conclusion: A new whitening toothpaste containing hydrogen peroxide delivers in-vitro whitening efficacy which is superior to a commercial whitening toothpaste that does not contain hydrogen peroxide.