Study protocol of a cluster randomized controlled trial on oral health promotion programs for adolescents in Iran.

To design and evaluate oral health promotion programs for high school students in underprivileged areas of Tehran Province. A multilevel intervention based on the PRECEDE-PROCEED model will target students aged 13-15 years across 18 schools in Southern Tehran, Iran. This randomized controlled trial is being conducted using multistage random sampling, 435 students in grades 7-9 will be divided into three groups: Comprehensive Intervention (CI), Less Comprehensive Intervention (LCI), and a control group. The CI group will receive interventions including group motivational interviewing for students and teachers, parental education, free oral hygiene kits, peer-supervised tooth brushing, and access to educational videos through the school learning management system. The LCI group will receive similar interventions, excluding supervised tooth brushing. The control group will follow routine oral care practices. Primary outcomes will include oral health knowledge, attitudes, and practices; secondary outcomes will comprise plaque and CAST (caries assessment spectrum and treatment) indices. Data collection will occur at baseline, and at 3- and 12-months post-intervention. Statistical analysis will assess the effectiveness of the interventions. This study aims to provide evidence for embedding oral health promotion in school curricula. Results could inform national public health strategies to improve adolescent oral health.