Method: This was a 5-week treatment, parallel groups, double-blind, randomized and controlled clinical trial in which the whitening dentifrice (Crest 3DWhite Luxe®) was compared with a negative control dentifrice (Colgate® Cavity Protection). The study model involved 2-week of stain induction followed by 5-week of treatment duration to assess the stain prevention efficacy. To induce stain, a sufficient number of subjects received a dental prophylaxis, and then began a brushing and tea rinsing regimen. Sixty healthy adults with sufficient stain accumulation enrolled into the treatment phase of the study. Following baseline examination, subjects received a dental prophylaxis and were randomly assigned to one of the two treatment groups. Subjects brushed twice daily and used tea rinsing three times a day for 5 weeks. Clinical examination by an experienced dental examiner using the Interproximal Modified Lobene (IML) stain index was conducted at BL, week 2 and 5. Analysis of covariance (ANCOVA) with treatment as a factor and Baseline Lobene score as the covariate was used to assess treatment differences. All comparisons were two-sided using a 5% level of significance.
Result: Baseline IML stain scores were balanced between the two treatment groups (p=0.57), with means of 2.89 and 2.96 for the pyrophosphate and the negative control dentifrices, respectively. At week 5, the adjusted mean IML score was 0.25 for the pyrophosphate group and 0.80 for the negative control group. The pyrophosphate containing dentifrice provided statistically significant extrinsic stain prevention efficacy after 5-week of product usage (p < 0.0001), representing 68.4% less stain accumulation relative to the negative control. All test products were well tolerated.
Conclusion: The research demonstrated the superior stain prevention efficacy of a pyrophosphate containing whitening dentifrice relative to a negative control dentifrice.