Evaluation of Extrinsic Stain Reduction Efficacy of Two Tooth-whitening Dentifrices

OBJECTIVEs: This trial were to evaluate the extrinsic stain removal efficacy of two novel whitening dentifrices: 1) A containing 3% Polyethylene Glycol-400 and 2% Alumina (Lion® Zact® double effect) and 2) B containing 2.5 % Polyethylene Glycol-400 and 0.5% Tetrasodium Pyrophosphate (Lion® Zact® Intensive Fresh), both compared to a commercially available dentifrice which was not declared to have whitening efficacy. Methods: This study was a randomized, eight-week, double-blind, and three parallel groups, clinical trials. 148 healthy adults (100% smoker) with visible extrinsic stain on 12 anterior teeth are quantified into this study. Subjects were randomly assigned to one of three treatments and instructed to brush with the assigned dentifrice and a soft-bristled adult toothbrush for two minutes twice daily(morning and evening) at home for the duration of this study. Efficacy was evaluated by modified Lobene examination on anterior teeth at baseline and at week 4 and at week 8. RESULTS: 121 subjects (male smokers aged from 19 to 60) completed the entire study and no an adverse event was reported. Both test groups showed statistically significant reductions in Lobene stain scores at week four (p<0.05) and week eight (p<0.05) relative to baseline. Following 8 weeks of brushing, compared to negative control group, the experimental dentifrice A reduced stain scores of 15.31% in stain area and 12.65% in stain intensity. Similarly, dentifrice B reduced stain scores by 14.83% in stain area and 13.86% in stain intensity. The mean changes differ significantly between the two test groups and control group (P<0.01, One-way ANOVA). CONCLUSION: This study showed both text toothpastes containing 3% Polyethylene Glycol-400,2% Alumina or 2.5 % Polyethylene Glycol-400, 0.5% Tetrasodium Pyrophosphate significantly reduce extrinsic tooth stain of tobacco use compared to the control toothpaste.

Acknowledgments: This study was supported by The Lion Daily Necessities Chemicals (Qingdao) CO., LTD，China.