Caries prevalence in 2.5-year-old children.

The prevalence of caries and gingivitis was determined clinically in 2.5-year-old children (n = 832) living in the southern suburbs of Stockholm. The occurrence of mutants streptococci and lactobacilli was determined in samples taken from the tongue and the buffer capacity of the saliva was measured. The parents answered a structured questionnaire concerning their children's dietary habits, oral hygiene, fluoride exposure and their social and ethnic background. Initial or manifest caries was diagnosed in 11.7 and 6.4% of the subjects, respectively. Seventy-two percent of the total number of caries lesions were localized to the maxillary incisors. Caries prevalence in children with an immigrant background was significantly higher (p < 0.001) than in children without. In the multivariate analysis, the variables significantly associated with caries were: colonization with mutans streptococci (p < 0.001), lactobacilli (p < 0.01) and children with immigrant background (p < 0.01). The study demonstrates an association between early colonization of cariogenic microflora and an increased risk of developing dental caries in very young children.