The effect of xylitol chewing gum on mutans streptococci in saliva and dental plaque.

Dental caries are one of the most common infectious diseases occurred in Thai children. The chewing of xylitol, sorbitol, and even sugar gum has been suggested to reduce caries rates. The aim of the present investigation was to evaluate the effect of xylitol chewing gum on mutans streptococci (MS) in saliva and dental plaque. Ninety-one children, aged 10-12 years, with more than 1 x 10(5) MS per milliliter of saliva were included in this study. They were divided into three groups balanced according to their MS counts at baseline: one control group (no supervised gum use), and two xylitol groups (supervised 55% and 100% xylitol gum use). Whole saliva and pooled plaque samples were obtained after 90 school days. When comparing the MS counts between the groups, those chewing 100% and 55% xylitol gum showed significant reductions (p < 0.025), but a dose response effect was not demonstrated. Chewing 100% xylitol gum caused significant reductions on salivary MS scores (p < 0.025) which was little different from the 55% xylitol group. The results suggest that the use of xylitol chewing gum can reduce the levels of MS in plaque and saliva.