A Prospective Longitudinal Study of Early Childhood Caries Onset in Initially Caries-Free Children.

Introduction: Early childhood caries (ECC) is a complex oral disease that is prevalent in US children.

Objectives: The purpose of this 2-y prospective cohort study was to examine baseline and time-dependent risk factors for ECC onset in initially caries-free preschool children.

Methods: A cohort of 189 initially caries-free children aged 1 to 3 y was recruited. At each 6-mo study visit, children were examined using the ICDAS index; salivary samples were collected to assess mutans streptococci (MS), lactobacilli, Candida species, salivary cortisol (prior and after a stressor), and salivary IgA. Diet and oral health behavior were assessed from parent report. Child and family stress exposure was assessed from measures of psychological symptoms, stressful life event exposure, family organization and violence exposure, and social support. Sociodemographic factors were also considered. A Kaplan-Meier estimator of survival function of time to ECC and a Cox proportional hazards model were used to identify predictors of ECC onset.

Results: Onset of ECC was associated with high salivary MS levels at baseline (log-rank test, P < 0.0001). Cox proportional hazards regression showed that the risk of dental caries significantly increased with salivary MS in log scale over the 6-mo period (hazard ratio, 1.08; P = 0.01). Other risk factors in the model did not reach statistical significance.

Conclusion: Our results provide prospective evidence that an increase in salivary MS predicts ECC onset in young, initially caries-free children, confirming that a high salivary MS count likely plays a causal role in ECC onset, independent of covariates.

Knowledge transfer statement: These results suggest that we must focus on reducing salivary MS counts in young children and preventing or delaying MS colonization in infants and young children determined to be at risk for ECC.