What Is the
Connection between Anaerobic Metabolism and Dental Plaque?
Dental caries, or tooth decay, is one of the most prevalent diseases in the United States and possibly in the world, although modern treatments such as fluoride and flossing have greatly reduced its incidence in young people. Contributing factors in tooth decay are a combination of a diet high in refined sugars, the development of dental plaque, and anaerobic metabolism.
The high-sugar diet allows for rapid growth of bacteria in the
mouth, and sucrose is perhaps the most efficiently used sugar because the
bacteria can make their polysaccharide “glue” more efficiently from this
nonreducing sugar. The bacteria grow in expanding sticky colonies, forming
plaque on the tooth surface. The bacteria growing under the surface of the
plaque must utilize anaerobic metabolism because oxygen does not diffuse
readily through the waxy surface of dental plaque. The two predominant
by-products, lactate and pyruvate, are relatively strong organic acids, and
these acid products actually destroy the enamel sur-face. The bacteria, of
course, grow rapidly in the pock holes. If the enamel is eaten all the way
through, the bacteria grow even more readily in the softer dentin layer beneath
Fluoridation results in a much harder enamel surface, and the
fluoride may inhibit the metabolism of the bacteria. Daily flossing disrupts
the plaque, and the anaerobic conditions never get started.