Potential associations between the levels of specific microorganisms in saliva and the level of dental caries in U.S. adolescents were investigated. Initial findings indicate that there is a positive correlation between the level of S. mutans and Lactobacillus in saliva and the prevalence of dental caries in this study population. The caries prevalences for participants having high levels of bacteria in saliva were 1.5 DMF surfaces higher than the corresponding prevalence for those having low levels of bacteria in saliva.