The prevalence of mutans streptococci (MS) was evaluated in samples of unstimulated saliva from 142 12-31-month-old children. Initial and manifest caries of all teeth surfaces were recorded. Mutans streptococci were detected in 80.3% (n = 114) of the studied children, and 21.8% of all children (n = 31) presented high levels of these microorganisms. The salivary levels of mutans streptococci depended on the number of erupted teeth (<FONT FACE="Symbol">c</font>2 = 19.03; p < 0.001). There was a positive association between the number of caries affected children and the salivary levels of MS (<FONT FACE="Symbol">c</font>2 = 28.67; p < 0.001). In addition, there was a positive correlation between the salivary levels of these microorganisms and the number of caries lesions which was higher when initial caries were considered (r = 0.537; p < 0.001). These data show a high prevalence of mutans streptococci in children with 12 to 31 months of age and its positive association with the frequency and severity of dental caries.
Streptococcus mutans; Dental caries; Primary dentition
