Publication:

Effect of dentifrices containing sorbitol, combination of xylitol and sorbitol on salivary Streptococcus mutans and Lactobacillus counts in 14-15 year old children: a randomized trial

Background Xylitol, a naturally occurring sugar alcohol which cannot be fermented by oral microorganisms has been shown to reduce Streptococcus mutans levels in plaque and saliva and to markedly reduce tooth decay. Studies have proved that combination of xylitol and sorbitol added in chewing gum is more effective in reducing tooth decay compared to xylitol alone. Purpose of this double blinded, parallel, randomized trial was to compare the relative effect of sorbitol and combination of xylitol and sorbitol containing dentifrices on salivary Streptococcus mutans and Lactobacillus in a group of high school children.

Methods Sixty school children with age group of 14-15 years were randomly allocated into 2 study groups (S-sorbitol containing dentifrice and X+S- Xylitol and Sorbitol containing dentifrice), with 32 participants in each group. Subjects were asked to use the experimental dentifrices twice daily for 3 months period. Resting whole saliva was collected at baseline, at the end of 1 month, 2 months and 3 months interval after the use of assigned dentifrice. Saliva samples were used for microbial analysis. Streptococcus mutans was cultured on Mitis salivarius bacitracin agar and Lactobacilli on Rogosa SL agars. Results were expressed in frequencies. Nonparametric tests namely Wilcoxons-signed rank test and Mann Whitney U test were used for testing the statistical significance. The level of significance was set at p=0.05.

Results There was no significant difference in salivary Streptococcus mutans count amongst the two groups at baseline (p=0.271). There was no significant difference in counts of Streptococcus mutans and lactobacilli among the subjects in the sorbitol containing dentifrices (S) group at different time intervals of the study whereas there was significant reduction in counts of Streptococcus mutans and Lactobacillus count among the subjects in the xylitol and sorbitol (X+S) containing dentifrices at all the time interval. At the end of 3rd month interval there was significantly low Streptococcous mutans and lactobacilli count for X+S group compared to S group with p<0.001 and p=0.02 respectively.

Conclusions The use of dentifrices containing combination of xylitol and sorbitol, twice daily showed significant antimicrobial properties against salivary Streptococcus mutans and lactobacillus by the end of 3 month compared to sorbitol containing dentifrice.