Use of the strip mutans test in the assessment of caries risk in a group of preschool children.

The purpose of this study was to evaluate the use of a chair-side test involving a count of salivary mutans streptococci (the Strip mutans test) in the assessment of caries risk in a group of preschool children living in an area with a low caries prevalence. A group of 528 4-year-old children were randomly allocated to a study or a control group. In the study group, the baseline microbial data, together with clinical findings of past caries experience, were used for caries risk assessment and for planning subsequent preventive treatment. All children were examined at baseline and after 2 years. Caries experience was assessed according to WHO criteria. There was no difference in caries experience between the study group and the control group at baseline. Within the study group, caries increment was positively correlated (P < 0.01) with the number of mutans streptococci in saliva at baseline, and children assessed 'at risk' at baseline (Strip mutans score > or = 2 and/or > or = 1 dmfs) developed more new lesions than those considered as 'low risk' (mean dmfs 2.6 v 0.9; P < 0.05). The sensitivity and specificity of this combined clinical and microbial caries risk selection were 67% and 75%, respectively, disease being defined as an increment of at least one carious lesion over the 2-year period. In both groups, 50% of the children remained caries inactive during the study. The mean caries increment was, however, lower in the study group than in the control group (mean dmfs 1.7 v 2.1) but the difference was not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)