Lactobacilli in human dental plaque and saliva.

Lactobacilli were isolated from about 50% of plaques from sound tooth surfaces of human subjects who had ingested fluoride (F) supplements since their births or subjects with negligible systemic fluoride exposure. In about 10% of these plaques, the proportions were 1% or higher of the total flora. Lactobacilli were not always isolated from caries-associated plaques. The mean salivary lactobacillus count of the F-supplement group was comparable to that generally reported for other groups of caries-active subjects with varying caries experience. The findings are discussed in relation to the role of lactobacilli in caries initiation and the anti-caries effect of fluoride supplementation.