A sample of approximately 200 children of Hispanic ancestry who are participating in a sealant project in East Los Angeles are being clinically and microbiologically examined. Questionnaires to check residency and heritage information are obtained. Participants are in grades two and three. A dental examiner, screening minority children for larger sealant study, is examining deciduous and permanent molars for dental caries according to NIDR criteria. Microbiological specimens are collected using the salivary rinse system designed for NIDR National Survey of Children. Determination of mutans streptococci and lactobacillus counts are being made in the laboratory at the University of Southern California. Analyses of relationships between dental caries status and microbiological counts are under way.