A randomized clinical study investigating the staining profile of an experimental stannous fluoride dentifrice

The primary objective of this study was to investigate the staining profile of an experimental test dentifrice containing 0.454% w/w stannous fluoride compared to that of a marketed control dentifrice containing 0.76% w/w sodium monofluorophosphate (Colgate Cavity Protection) following regular and repeat use, with twice daily brushing over 8 weeks. As an exploratory objective, the staining profile of the test dentifrice was compared to that of a marketed comparator dentifrice containing 0.454% w/w stannous fluoride (Crest Pro-Health - Clean Mint).

This was a single-center, examiner-blind, randomized, three arm, parallel group study, stratified by pre-baseline stain score [total Lobene Stain Index (LSI) (area x intensity) score < 31, > or = 31] and smoking status. Following initial screening, 137 healthy subjects, aged 18 years and above, with 12 gradable anterior teeth returned for baseline assessments. At the baseline visit, subjects received an oral soft tissue (OST) examination and an assessment of extrinsic dental stain using the LSI on the facial and lingual surfaces of the 12 anterior teeth, LSI area, LSI intensity and LSI area x intensity (the LSI area x intensity score was termed the pre-baseline LSI score). Subjects who met study requirements received a dental prophylaxis of the anterior teeth to remove all visible stain from their tooth surfaces such that an LSI (area x intensity) score of 0 was achieved. Randomized subjects brushed with their assigned dentifrice at home twice daily for 1 timed minute and returned after 4 and 8 weeks for an OST examination and dental stain assessment of the anterior teeth using LSI.

There were no statistically significant differences in dental stain build-up between the test dentifrice containing 0.454% w/w stannous fluoride and a marketed control dentifrice (Colgate Cavity Protection), after 4 and 8 weeks of twice daily brushing, in terms of LSI area x intensity, LSI area or LSI intensity scores. Exploratory analysis indicated that the marketed stannous fluoride dentifrice (Crest Pro-Health) exhibited more dental stain build-up at 4 and/or 8 weeks compared to the other two study dentifrices. However, post-hoc analysis revealed an imbalance in LSI baseline stain levels between the treatment groups, with higher stain levels in the marketed comparator group, which made it difficult to draw robust conclusions from the exploratory data. This imbalance was not considered to impact the other study analyses. Study treatments were well tolerated.