Potential cariogenicity of low and high sucrose dietary patterns.

In vivo daytime plaque pH telemetry during 2 week periods was combined with measurement of changes in enamel microhardness and analysis of microbial plaque composition in 2 human subjects. Well defined sucrose rich and sucrose poor diets were used as variables. During the 2 weeks of the high sucrose diet (50-80 g/day), a high cariogenic acid attack calculated from pH changes in "Proton hours" was associated with a marked progressive decrease in enamel microhardness. The low sucrose diet (2-6 g/day) showed a low "Proton hour" acid attack during the entire 2 weeks. The decrease in enamel microhardness, however, was low only during the first week. After day 7 a marked decrease could be observed. It could not be explained by the glycolytic activity of the plaque, which was low. Streptococcus mutans was present in all microbial samples.