Microbial and salivary conditions in 9- to 12-year-old children

The prevalence of S. mutans and lactobacilli, the salivary secretion rate, and salivary pH and buffer capacity were examined in 655 children 9-12 years old. Some of these factors were correlated with the frequency of caries. Positive correlations were observed between for example S. mutans and lactobacilli, between S. mutans and incipient smooth surface caries, and between lactobacilli and open carious lesion. A high proportion of the children showed large numbers of S. mutans and lactobacilli.