Antimicrobial effects of a stannous fluoride toothpaste in distinct oral microenvironments

Background. Clinical research has shown a relationship between microbial accumulations and oral diseases such as gingivitis and caries. The mouth harbors large densities of bacteria in distinct oral microenvironments, that is, dental plaque on teeth, saliva, and soft tissues such as the tongue, cheek, and gingiva. In this home-use study, the authors compared the effects of brushing with a newly formulated stannous fluoride toothpaste and a sodium monofluorophosphate dentifrice on bacteria of distinct oral microenvironments. Methods. Adult participants completed a washout phase before baseline sampling of dental plaque, saliva, and scrapings from tongue, cheek, and gingiva, which were used for microbiological analysis. Treatments were randomly assigned: test (62 participants) and control (67 participants) for twice-daily toothbrushing over 8 weeks. After 4 weeks and 8 weeks, posttreatment samples 12 hours after brushing were collected for analysis. At these posttreatment visits, participants brushed in the dental clinic, and an additional sample was collected 4 hours later for microbiological analysis. Results. Relative to the control, 12 hours after brushing, the test toothpaste showed greater reductions of bacteria (ranging from 14% to 27%) at the 4-week evaluation, which increased to 27% to 41% after 8 weeks of brushing. Correspondingly, 4 hours after brushing with the test toothpaste at the 4-week evaluation, there were greater reductions of bacteria in the range of 22% to 59%, which increased to a range of 33% to 61% at the 8-week assessment for participants completing the study. Conclusions. The stannous fluoride toothpaste provided bacterial reductions in all oral microenvironments 12 hours after brushing. In addition, the authors observed microbial reductions 4 hours after brushing, which increased after extended use. Practical Implications. The results are appropriate for oral hygiene recommendations by dental professionals.