In-vitro Tooth Stain Removal Efficacy of a Low Peroxide Toothpaste

Objectives: This in-vitro study evaluated the stain removal efficacy of, a low peroxide whitening toothpaste as compared to a placebo.
Methods: Two test toothpastes were prepared, one with low peroxide (EW) and a placebo. Extracted human molars were split into halves and mounted in a tray. The teeth were brushed using commercially available non-peroxide toothpaste for 20 minutes. A 1:1 slurry of dentifrice to artificial saliva was added into the brushing tray. The teeth were brushed using Colgate 360 toothbrush with 250 g of pressure for 2 minutes. The brushing machine was set to 120 strokes/min. After 2 min, brushing was stopped, the slurry was removed, and the teeth were rinsed with 100 g of deionized water. The teeth were gently blotted with a paper towel to remove excess liquid. Measurements were taken with the Spectrophotometer,. The brushing treatment and measurement cycle was repeated 56 times to mimic twice daily use of each product for 28 days. Teeth were tested in sets of five and a total of 10 teeth were tested for each product. The L*, a*, and b* values were used to calculate the change in the whiteness index for each tooth after each treatment as compared to baseline. The final values of ΔW were reported. The difference between the two products was evaluated after each treatment with the General Linear Model using the Tukey method and a 95 % confidence interval.
Results: The change in ΔW after 56 brushings was 1.4+0.2 for the placebo, and -4.2+1.6 for the EW toothpaste. The ΔW results of the two products are significantly different from each other.
Conclusions: The in-vitro tooth whitening efficacy provided by EW is significantly better than the placebo. Therefore, these results support that the peroxide in the toothpaste boosts the removal of more tooth stains over time.