Very High Salivary Streptococcus Mutans Predicts Caries Progression in Young Children.

PURPOSE: Culturing mutans streptococci (MS) from children's saliva has high utility in caries risk assessment. The purpose of this retrospective cohort study was to examine its ability in predicting caries progression and determine sensitivity, specificity, and likelihood ratios of a very high ["too numerous to count (TNTC) MS test result. METHODS: 200 preschoolers (3.3+/-1.2 years, 50 percent no recoverable MS, 50 percent TNTC MS at first dental visit) were followed for five or more years. Caries experience of both groups was compared to identify predictors of caries presence and its progression. RESULTS: Controlling for demographic, oral health, and dental visit factors, TNTC preschoolers had both greater presence and extent of caries at the first dental visit (adjusted odds ratio [aOR] 8.0, 95 percent confidence interval [CI] 2.5 to 25.5) and caries progression at five or more years (aOR 6.0, 95 percent CI 2.4 to 15.0). Fewer TNTC preschoolers remained caries free over five years or longer (13 percent versus 77 percent for no MS). Overall, sensitivities and specificities exceeded 75 percent. CONCLUSIONS: Despite engagement in preventive dental care, children with TNTC MS were six times more likely to experience cavity increments than preschoolers with no recoverable MS at first visit.