In Vitro Whitening Potential of a Peroxide-containing Mouthwash vs Placebo

To evaluate the in-vitro anti-stain potential of Colgate® Optic White^TM mouthwash, containing 2% hydrogen peroxide against a non-peroxide placebo mouthwash. 

Method:

Colgate® Optic White^TM mouthwash, containing 2% hydrogen peroxide, and a placebo mouthwash were evaluated in a blinded, in-vitro laboratory assay. Saliva coated hydroxyapatite discs were treated with mouthwash and then rinsed with water. The treated discs were then soaked in a stain mixture of coffee, tea, and wine for 15 minutes, rinsed with water, soaked in saliva for 20 minutes, then rinsed with water again. This challenge cycle was repeated for an additional two times.  Following the three challenge cycles, the discs were again treated with the mouthwash.  A spectrophotometer was used to collect  L*, a*, and b* values of the hydroxyapatite discs at baseline, prior to the first mouthwash treatment, following each staining procedure, and also following the second mouthwash treatment.  The color change index (ΔE) from the baseline was then recorded.  Since the baseline color of the untreated HAP disc is pristine white, the smaller the ΔE, the whiter the disc appears after the treatments.  A 2-sample t-test was conducted to compare the mean ΔE value for each product with a p<0.05 indicating significant differences between products. 

Result:

After the second mouthwash treatment, the 2% peroxide containing mouthwash showed a mean ΔE of 8.696 and the placebo mouthwash showed a mean ΔE of 30.945. Based on the 2-sample t-test, the Optic White mouthwash exhibited a superior whitening effect which was statistically significantly better than the placebo mouthwash (p<0.01). 

Conclusion:

Colgate® Optic White^TM mouthwash demonstrated in-vitro whitening potential which is superior to that of a matching placebo mouthwash.