PROJECT SUMMARY/ABSTRACT Dental phobia is associated with avoidance of proper dental care, poor dental health, and decrements in social and oral quality of life. Although dental phobia may persist for many years, the disorder usually first manifests during childhood or adolescence. Hispanic youth may be at particularly high risk of developing dental phobia because, on the whole, Hispanic/Latino families are less likely to take a preventative stance toward dental health? meaning that Hispanic youths' first encounters with a dentist are more likely to be for treatment that is associated with pain, discomfort, or shame ? the types of learning experiences related to the development of dental phobia. While our knowledge about the etiology of dental phobia is somewhat well developed, we know considerably less about how to treat it. Recently, however, a one-session exposure therapy treatment (OST) for specific phobias has proven successful in addressing a variety of phobias in youth, but youth with dental/medical phobias have not been included in the trials assessing OST because of the need to include medical professionals in the treatment. However, we have been able to build a research team that includes academic and practicing dentists. Therefore, the aim of this project is to prepare for a trial testing the effectiveness of OST for dental phobia in children and adolescents. More specifically, we propose to prepare the manual of procedures, training manuals, and IRB application necessary for the submission of a U01 application to test the effectiveness of OST compared to treatment as usual (TAU) delivered by dental hygienists in the Rio Grande Valley (RGV) of Texas ? an area with a very high concentration of Hispanic youth at risk for dental phobia. This clinical trial would randomize dental clinics in the RGV to one of the two treatment arms (OST vs. TAU) so that patient response, treatment feasibility (including provider response to treatment and cost-effectiveness), as well as a hypothesized mediator of treatment can be assessed. It is expected that OST can provide a feasible and effective treatment option that can be delivered by hygienists in the dental office. That is, that the treatment can decrease both anxiety and phobic avoidance in youth while giving treatment providers a cost-effective option that will be more acceptable to children and their parents when compared to current treatments such as sedation and restraint. Moreover, although exposure therapy has a high level of empirical support in youth and a good deal of laboratory work has been conducted to develop the theory to explain its effects, to our knowledge, the main hypothesized mechanism of action ? inhibitory learning ? has not been studied within the context of a clinical trial; therefore, the study we propose could advance our understanding of the mechanism driving one of the most promising treatments for individuals with anxiety disorders.