In vitro effect of tobacco on the growth of oral cariogenic streptococci.

Most pouch and plug chewing tobaccos with high sugar contents are able to support the growth of S mutans and S sanguis in vitro. Snuff and unprocessed tobacco, although not able to stimulate growth of these organisms, do not inhibit growth. Inhibitory agents present in tobacco leaves do not preclude use of tobacco sugars by the organisms tested. Because factors other than bacterial populations play an important role in caries initiation, clinical studies are needed to identify the effects of commercial tobacco on the human dentition.