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 Hispanic/Latino families are less likely to take a preventative stance toward dental health. This means 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. Although our knowledge about the etiology of dental phobia is well developed, we know considerably less about how to treat dental phobia in youth. Recently, a one-session exposure therapy treatment (OST) for specific phobias has proven successful in addressing a variety of phobias in children and adolescents. However, youth with dental/medical phobias have not been included in the trials assessing OST because of the need to include dental health professionals in the treatment. Therefore, the primary goal of this application is to prepare for and conduct a Stage III trial comparing OST for dental phobia in children and adolescents to an active control treatment in a predominantly Hispanic population and to examine inhibitory learning as the mechanism responsible for changes in anxiety and fear. The aims of the UG3 phase are to do the preparatory work needed for the trial, including the development of all study documentation and finalizing the clinical sites. Additional plans during the UG3 phase include the assessment of the acceptability and feasibility of the study procedures and a trial examining whether youth treated with OST show evidence of changes in inhibitory learning. The primary aim of the UH3 stage is to examine the efficacy of OST in a Stage III social/behavioral clinical trial in which OST is delivered by dental hygienists. This trial would randomize dental clinics to one of the two treatment arms (OST vs. Control) so that patient response and the hypothesized mechanism of treatment can be assessed. Factors related to future dissemination and implementation efforts will also be examined. It is hypothesized that OST can provide an efficacious 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. 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 explains its effects, the main hypothesized mechanism of action – inhibitory learning – has not been studied as a mediator within the context of a clinical trial; therefore, this work could advance our understanding of the mechanism driving one of the most promising treatments for individuals with anx...