RESUMO
PURPOSE: The school environment may positively influence student health behaviours and learning. This study aimed to investigate the association between cities' quality of education and adolescent students' oral health-related behaviours. METHODS: Cross-sectional study using data of the 2015 Brazilian National Adolescent School-Based Health Survey and other public databases. The sample was composed of adolescents (N = 23,674) from public schools of the 27 Brazilian state capitals. Outcomes were four oral health-related behaviours: toothbrushing, sweets and soft-drink consumption, and dental visits. The explanatory variable was the cities' quality of education, measured by the Brazilian Basic Education Development Index. Covariates were individual (sociodemographic) and contextual (socioeconomic, oral health coverage and oral health-promoting schools). Multilevel logistic regression was performed considering two levels: individual (adolescents) and contextual (city). RESULTS: The prevalence of the outcomes were: low daily toothbrushing frequency 6.7% (95% CI 6.0-7.4); high weekly sweets consumption 41.5% (95% CI 40.3-42.7); high weekly soft-drink consumption 28.5% (95% CI 27.2-29.9); and low frequency of annual dental visits 31.2% (95% CI 30.1-32.3). In the adjusted models, cities whose schools had higher scores of education quality were more likely to have students with low toothbrushing frequency and high frequency of sweets consumption. CONCLUSION: The cities' quality of education was associated with unhealthy oral health-related behaviours, particularly the frequency of toothbrushing and sweets consumption. Therefore, appropriate health promotion strategies as well as high-quality education are needed in schools.