Salivary levels of Bifidobacteria in caries-free and caries-active children

Abstract

Background: Salivary levels of Bifidobacteria have been shown to be significantly correlated with caries experience in adults but not as yet in children.

Hypothesis: Salivary levels of Bifidobacteria are positively associated with caries experience in children.

Aim: To compare the salivary concentrations of Bifidobacteria of caries-free and caries-active children.

Design: Saliva was collected using the tongue-loop method from 38 caries-active children and from 22 clinically caries-free children, and the numbers of Bifidobacteria, mutans streptococci, lactobacilli and yeasts were determined. Additionally, the age and gender of the children, a plaque index, sugar amount in diet, sugar frequency in diet, hygiene practice and fluoride toothpaste usage were recorded.

Results: Bifidobacteria were isolated from 95% of the caries-active children and from only 9% of the caries-free children (P < 0.001). Salivary levels of Bifidobacteria were significantly correlated with amount of sugar in the diet, frequency of sugar consumption and oral hygiene practice. The significant variables that discriminated between the caries-free and caries-active subjects were salivary levels of Bifidobacteria, salivary levels of mutans streptococci and oral hygiene practice (χ(2) = 72.57, P < 0.001) and overall 90.0% of cases were correctly classified.

Conclusions: Salivary levels of Bifidobacteria are significantly associated with caries experience in children. The salivary levels of this genus may be a useful marker of caries risk.