Reducing Oral Mutans Streptococci Levels with Xylitol Mouth Rinse

Xylitol-sweetened chewing gum has cariostatic properties, but is not suitable for all caries-prone patients. Objectives: The purpose of this study was to compare the effect of xylitol rinse and xylitol chewing gum on mutans streptococci (MS) load on the dentition. Methods: 202 subjects were screened for MS levels in paraffin-stimulated saliva. 104 qualifying subjects (i.e., ≥5 log CFU/ml) were randomly assigned to one of three groups. Positive control subjects (N = 34) chewed two xylitol gum pellets [Spry™, Xlear Inc., Orem, UT] for at least 5 minutes three times daily (xylitol dose: 4.3g/day). Experimental group subjects (N = 36) rinsed with 20ml of an 11%-aqueous solution of xylitol twice daily for 60 seconds (dose: 4.3g/day). Negative control group subjects (N = 34) did not use either product. No attempt was made to change the subject's diet. Salivary MS levels were monitored at one and three months. Compliance was very high as measured by use-diaries and exit questionnaires. Results: Mean MS levels [log CFU/ml (SE)] at baseline were 5.6 (0.1) in positive control, 5.5 (0.1) in experimental, and 5.5 (0.1) in negative control subjects. After 3-mos, MS levels were 4.4 (0.2) in the positive control, 4.4 (0.2) in the experimental, and 4.9 (0.2) in the negative control groups. Differences between groups were not significant by ANOVA (p = 0.2), however, MS levels tended to be lower in the experimental and positive control groups. Conclusion: Both xylitol rinse and chewing gum caused a similar reduction in MS levels on the dentition. This effect might be increased by altering exposure time, concentration, etc. Larger studies will be needed to determine if xylitol rinse can reduce caries incidence in high risk populations. Supported by the Minnesota Oral Health Clinical Research Center.