Role of microbiological factors in predicting early childhood caries.

PURPOSE: Microbiological methods that accurately identify caries-susceptible children may enhance caries control and assist treatment planning. This study's purpose was to evaluate the usefulness of two microbiological indicators (mutans streptococci [MS] and lactobacilli [LB] levels), singly and in combination, for predicting early childhood caries (ECC) and their contributions in multifactorial modeling. METHODS: A total of 1,782 randomly selected three- to five-year-olds were recruited and underwent oral examination and microbiological tests using commercially available diagnostic kits. A questionnaire was completed by their parents. After 12 months, the caries increment in 1,576 (∼88 percent) children was assessed. RESULTS: Caries risk increased with the MS and LB levels but plateaued above the LB level of 10(5) CFU/ml saliva. MS, LB, and combined MS+LB models predicted one-year caries increment (Δdmft>0) with a sensitivity/specificity of 79 percent/67 percent, 51 percent/89 percent, and 66 percent/85 percent, respectively. Sensitivity/specificity reached 80 percent/80 percent when baseline caries experience ("past caries") was added to the MS+LB model and up to 85 percent/80 percent and 81 percent/85 percent when psychosociobehavioral factors and oral hygiene status were added to the MS+LB model, without and with "past caries," respectively. CONCLUSIONS: The combined "mutans streptococci+lactobacilli+past caries" model is useful for identifying at-risk children. Incorporating MS and LB into a biopsychosociobehavioral model slightly improved the prediction, even without "past caries".