Dental caries, the most common chronic disease of childhood, is a largely preventable disease. This proposal focuses on addressing inequities in dental caries experience among preschool aged U.S. children. It has been inspired by the shift and increase in dental caries among subsets of the population (i.e., 2-5 year old children, especially from underserved/minority population groups) that calls for a greater focus on targeted healthcare. In an environment of increasing healthcare costs and resource constraints, this approach is paramount in addressing oral health disparities. Because children have multiple well-child pediatric visits in the early years of life, many lower socioeconomic status (SES) and minority children have much greater access to medical care than to dental care. Our long-term goal is to reduce disparities in dental caries experience in young children in the U.S. by developing effective risk-based caries preventive and therapeutic strategies to be delivered through new models for oral health care, including primary medical healthcare settings. However, the problem is that currently there is no practical, validated and easily-scored tool practitioners can use to accurately and reliably assess, and effectively triage children at the highest risk for caries. Such an urgently needed tool will be developed in this proposed research. Thus, the objective of this study is to validate a caries risk questionnaire in order to develop a practical and easily-scored caries risk tool for use in primary medical healthcare settings to identify young, diverse U.S. children (1-4 years of age) with the highest risk for the development of caries. This will be accomplished by having the parents of 1,326 infants complete a caries risk questionnaire and by performing caries examinations on the children at baseline (child's age 12 + 3 months old), and again at 18 months (child's age 30 + 3 months) and 36 months after the baseline (child's age 48 + 3 months) to monitor the caries disease process, and how well the risk tool predicts caries risk status as the child ages. A great strength of this proposal is that it involves four experienced investigator groups who offer strong partnerships between medical and dental teams, and three study sites with well established primary care medical research networks that provide access and facilitate follow up to a variety of at-risk, diverse populations, including ethnic and racial minorities and low SES groups. Each study site also has an NIH Clinical and Translational Science Awards (CTSA), and will benefit from infrastructure and experience in longitudinal clinical translational research. The significance of this work is that identification of high caries risk children in primary healthcare settings allows cost-effective preventive and/or referral strategies to be developed, targeted and used in these settings to prevent early childhood caries. This will have immediate broad impact and influence on existing dental and medical policies and programs regarding screening and prevention of dental caries among young children from diverse disadvantaged and underserved subgroups, in primary medical and dental pediatric healthcare settings.