The effects of xylitol on mutans streptococci in children

Objectives: 1) To investigate the effect of three different doses of xylitol on mutans streptococci counts in saliva. 2) To compare the inhibition of S. mutans and S. sobrinus growth. 3) To evaluate the changes of salivary pH. Methods: Seventy one children that underwent removable appliances were randomly assigned into one of four groups. Stimulated saliva specimens were plated in duplicate on TYCSB agar for S. mutans and S. sobrinus. PCR amplification was performed to identify S. mutans and S. sobrinus. The salivary pH was measured using Dentobuff® Strip (Orion Diagnostica). Results: 1. After the 3-month period a significant decrease of the S. mutans counts occurred in the group B (one gum 3 times a day;P < 0.05) but not in control group. At the 2-month period a significant decrease of the S. mutans counts occurred in the group C (one gum 4 times a day; P < 0.05) and at the 2-month period of the group D (two gums 3 times a day; P < 0.05). 2. After the 4-month period a significant decrease of the S. sobrinus counts occurred in the group C and the group D (P < 0.05). 3. Of the 4 low buffer capacity, salivary pH of 2 children (50%) increased to high or middle buffer capacity. 4. Of 12 children with middle buffer capacity, salivary pH of 2 children (16.7%) increased. Conclusions: Xylitol use did reduce the levels of S. mutans than S. sobrinus. It has been suggested that a daily intake of 3 tablet (about 4g) for 3 or 4 times a day is needed in order to obtain a clinical anticariogenic effect.