In Vitro Stain Removal Efficacy of a New Whitening Toothpaste

Objectives: The study described in this paper aimed to assess in vitro, the stain removal efficacy of a new whitening toothpaste (1450ppm NaF) containing silica abrasive. Methods: Stain removal efficacy was assessed using the Pellicle Cleaning Ratio (PCR) method (Int. Dent. J. 55: 197-202, 2005). Stained enamel blocks were randomly allocated to 4 toothpaste groups (new silica toothpaste, two clinically proven whitening toothpastes and a standard silica fluoride toothpaste), n=10/group. The method involves depositing a stained film on bovine enamel slabs over a period of time and subsequently using toothpaste products to remove the stain using a mechanical brushing procedure. This paper reports a modified version of the PCR method, where the PCR value is assessed by the removal of stain after brushing by measuring the change in stain level using a Chroma Meter. After the brushing treatment, all visible stain is removed using flour of pumice and the PCR value is calculated as a percentage of this value. Results: The PCR results [mean (SD)] for the new whitening formulation, two positive control whitening silica toothpastes and standard silica fluoride toothpaste were respectively: 55.75 (5.09), 53.75 (3.33), 52.68 (3.76) and 41.70 (4.94) % Cleaning. The new toothpaste and the two positive control whitening pastes showed significantly better cleaning than the standard fluoride paste (p<0.05); the differences between the three whitening pastes were not statistically significant. Conclusions: The study shows that the new whitening toothpaste formulation is as effective in extrinsic stain removal as the two clinically proven whitening toothpastes.