Relationship of microbial and salivary parameters with dental caries in Brazilian pre-school children.

Caries examination and collection of paraffin wax-stimulated saliva samples were performed in 37 children, 3-6 years old, in a child-care facility at the Vidigal slum, Rio de Janeiro, Brazil. The levels of mutans streptococci and lactobacilli in saliva were estimated by the Cariescreen and by the Dentocult tests and the saliva secretion rate was determined. Statistical analysis was performed on surface-based and patient-based caries prevalence rates (SBCPR and PBCPR), and related to bacterial and salivary parameters. The results show that 31 of the 37 children were caries active. The SBCPR for the primary dentition was 6.7% +/- 1.0%. Occlusal surfaces were the most affected by decay. Regression analysis revealed that mutans streptococci salivary levels were significantly associated with the SBCPR (P = 0.0001). Similarly, lactobacilli salivary levels were significantly associated with the SBCPR (P = 0.0001). No significant association could be found between the saliva secretion rate and the SBCPR. When regression analysis was used to model dependence of the SBCPR on both organisms, the mutans streptococci and lactobacilli salivary levels were significantly associated with the SBCPRs (P = 0.0021 and 0.0118, respectively), and salivary levels of these organisms accounted for 57% of the SBCPR variability. These findings indicate that the levels of mutans streptococci and lactobacilli in saliva are significantly related to the SBCPRs on the primary dentition of these children.