Screening preschool children for dental caries using a microbial test.

The present report describes the usefulness of a microbial caries screening test in a population of children younger than 6 years. Two hundred children presenting to a private pediatric dental office were screened for Streptococcus mutans using a test adapted for the dental office. The numbers of S. mutans colonies were recorded semiquantitatively and carious lesions were assessed clinically and radiographically. Ninety-three per cent of children with caries were positive on the test (sensitivity), while 57% of the infected children had caries (specificity). Uninfected children were almost always caries free (predictive value negative 95%). The results also showed an increasing percentage of children with caries in groups of children with increasing infection level. These findings are consistent with both the central role of S. mutans in caries initiation and the multifactorial nature of caries development. The dramatically better results in the present report may reflect a closer correlation between caries activity and S. mutans infection in younger than in older children. Microbial screening may be useful for identification of young children infected with cariogenic microorganisms so that preventive and therapeutic treatments can be tailored to the needs of individual patients.