Effect of xylitol gum on the level of oral mutans streptococci of preschoolers: block-randomised trial

Objectives: To assess the influence of xylitol chewing gum consumption on mutans streptococci level of 3–4 years old Japanese preschoolers. Methods: 248 participants were examined regarding caries‐related factors at baseline and were followed up at 6, 9, and 12 months after the baseline: assessors were blinded, subjects were open labelled and blocked parallel randomised; 142 were selected to use xylitol gum for 3 months (from months 6 to 9) and 106 were controls. Results: 161 participants were analysed (xylitol n = 76, control n = 85). Nineteen caries‐related variables, including xylitol gum consumption, were analysed for any association with the main outcome, plaque mutans streptococci scores development within the intervention period, by logistic regression. Six showed statistically significant associations by univariate analysis (P < 0.05). However, only xylitol gum consumption remained a significant negative association (P < 0.05) by multiple analyses. Interestingly, over 10% xylitol group children experienced diarrhoea, which was larger than previous investigations. Conclusion: Xylitol gum is effective in avoiding increased plaque mutans streptococci in young children.