Effect of a fluoride-containing varnish on Streptococcus mutans in plaque and saliva.

The effect of topical application of a fluoride-containing varnish, Duraphat, on the level of Streptococcus mutans in saliva and in dental plaque was investigated in schoolchildren. Samples of saliva and pooled buccal plaque were taken before varnish application and 4, 10 and 21 d after treatment. Fluoride varnish treatment with or without a preceding dental prophylaxis had no significant effect on the plaque and salivary levels of S. mutans. The findings suggest that the caries-reducing effect of fluoride varnish cannot be explained by an alteration of the incidence of S. mutans in dental plaque or in saliva.