1. The NIDCR funded Collaborating Research Centers to Reduce Oral Health Disparities (CRCROHD) represent an innovative approach to understanding determinants of oral health disparities, conducting research to address disparities, and translating research findings into action. Objectives: The NIH-funded Centers at the University of California San Francisco (U54DE019285), the University of Colorado Denver (U54DE019259), and Boston University (U54DE019275), with the support and encouragement of NIDCR, have organized as a research collaborative to take on the unusual and challenging task of working across wide geographical distances to design coordinated research studies that increase comparability and validity. A Data Coordinating Center is managed at UCSF. Methods: In six randomized clinical trials, the Centers are testing culturally appropriate interventions focused on preventing Early Childhood Caries (ECC) in vulnerable and minority populations. The studies share common baseline and outcome measures, as well as critical moderating and mediating variables. Three studies involve the use of fluoride varnish in community settings; two include the use of community workers to deliver interventions; two involve motivational interviewing; all involve extensive community participation. Study sites are diverse and include community health centers with medical and dental providers, participants' homes, and educational and social service agency settings. American Indian, Latino, and African- American populations are participating, as well as other underserved groups of young children and their families. Judith Albino, PhD, University of Colorado Denver, Aurora, CO, R. GARCIA, Boston University, Boston, MA, J.A. WEINTRAUB, University of California San Francisco, San Francisco, CA, and S.A. GANSKY, University of California San Francisco, San Francisco, CA. These centers are funded by the National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health, United States Department of Health and Human Services. Results: Common measures have been developed across studies to allow the Centers to address the efficacy of different interventions with common goals as well as distinctive aspects of research designs. Innovative approaches to ensuring community-based participation are being shared across the Centers as well. Conclusions: This collaborative research process is leading to comparisons of the efficacy of a variety of approaches and their use in populations that differ in needs, cultural expectations, and access to services. Characteristics of underserved populations, as well as product and process considerations, will play determining roles in the acceptability and effectiveness of preventive interventions. # 26 Motivational Interviewing Community Health Centers Community Based Clinical Interventions with Preschoolers Background: Motivational Interviewing (MI) is a specific health communication technology that has been used to address a wide range of health behaviors by actively engaging the client in developing a plan for change. With these two trials we hope to learn whether MI can improve oral health behaviors and reduce dental caries in young children. Study Designs: One urban (public housing) and one rural (in homes) research site. Non-health professionals will be trained to deliver MI sessions to parents of young children. Background: Accessing dental care continues to be difficult for low-income families, and primary medical care providers may provide a more readily available source of dental care. These trials assess whether fluoride varnish (FV), coupled with counseling and education offered in primary care or social service settings, can reduce ECC experience among children in low-income families. Study Designs: Both include urban settings and one involves a rural setting. Community health center clinicians will be trained to place FV. One study will compare oral health counseling methods by different types of providers with and without FV; the other study will compare FV applied by medical staff compared to referral to a dentist. This latter study also will take place within Women Infants and Children (WIC) supplemental nutrition programs for low-income families. Background: Preschool children from low income households are among those at highest risk for ECC. FV has a strong evidence base for caries prevention in primary teeth. Methods for expanding access to this preventive service are explored, including the use of trained community-based oral health educators and service providers. The use of FV in combination with Glass Ionomer Sealants and oral health counseling also will be tested in dental and non-dental settings. Study Designs: Non-dental and dental facility research sites. One group is testing parental counseling and fluoride-releasing Glass Ionomer Sealants with FV. The other group is testing education/counseling with FV. University of Colorado Denver Center for Native Oral Health Research (CNOHR) Boston University Northeast Center for Research to Evaluate and Eliminate Dental Disparities (CREED) University of California San Francisco Center to Address Children’s Oral Health Disparities (CAN DO) About the Collaboration The CRCROHD focused in the first year on developing a common core set of measures; these include study participant demographics, parental knowledge, attitudes, beliefs, behaviors related to early childhood oral health, dental services utilization, and clinical field assessments of caries in primary teeth. The Centers worked together to pilot test an innovative strategy for capturing data and measuring inter-rater reliability with caries examinations. Analyses also are being included to determine the relative costs of implementing community-based interventions across the centers. Each Center is implementing two clinical trials; the paired study descriptions below summarize critical elements in the research designs and community populations for each cross-institutional pair of studies. All trials utilize changes in caries incidence/increment (dmfs) as the primary outcome.