Oral Health Promotion Among Students in Special Education Schools: Protocol for a Multicity Cluster Randomized Controlled Trial.

Background: Children with disabilities attending special education schools face significantly higher risks of oral diseases, particularly dental caries, due to physiological, cognitive, and environmental challenges. However, school-based oral health interventions targeting this population are limited in China. Objective: This study aims to assess the effectiveness of fluoride varnish (FV) application, delivered alongside oral health education for parents and teachers, in improving the oral health of students in special education schools in Guangdong Province. Methods: This is a stratified, cluster randomized controlled trial conducted in Guangdong Province, China. Schools will be stratified by regional economic development level and randomly assigned to either an intervention or control group. The intervention group will receive annual dental examinations, biannual FV applications, and oral health education. The control group will receive standard annual examinations and comparable oral health education. Participants will be students aged 5 to 22 years enrolled in selected special education schools. Baseline assessments and 12-month follow-ups will include oral examinations and questionnaires assessing oral health knowledge, attitudes, and behaviors. The primary outcome is the difference in caries prevalence between the intervention and control groups at follow-up. Secondary outcomes include changes in oral hygiene behaviors and caregiver knowledge. Data will be analyzed using multivariable regression models adjusting for potential confounders and clustering effects. Results: This trial was funded by the Department of Education of Guangdong Province in 2025 (grant YCKJ-2025-30). As of June 2025, 12 special education schools across 3 cities had been enrolled (n=7, 58.3% intervention and n=5, 41.7% control schools), and more than 1100 students had been recruited. Baseline data collection and the first FV application are complete. Follow-up data collection is ongoing and is expected to conclude in June 2026. Data analysis has not yet started, and results are expected to be published in 2027. Conclusions: Biannual application of FV is expected to significantly reduce caries prevalence and improve oral hygiene behaviors among students in special education schools. This school-based intervention model aims to provide a scalable and evidence-based strategy to mitigate oral health inequities for children with disabilities in China.