Longitudinal evaluation of minimally invasive protocols for the prevention and control of dental caries in Brazilian schoolchildren: a multicentre study protocol.

INTRODUCTION: Dental caries remains one of the most prevalent chronic diseases in childhood worldwide. In Brazil, untreated carious lesions continue to affect oral health and quality of life in school-aged children. Minimally invasive approaches for caries management have demonstrated feasibility in community settings and may expand access to preventive and restorative care in socially vulnerable populations. METHODS: This multicentre longitudinal intervention study will recruit 50 000 children aged 6-12 years from public schools in five Brazilian cities (Santos, Ponta Grossa, Brasília, Fortaleza and Belém). All participants will undergo clinical examination using the International Caries Detection and Assessment System (ICDAS) and will receive preventive and educational measures, including oral health counselling, supervised toothbrushing with fluoridated toothpaste (1100 ppm F), toothbrushes, toothpaste and application of Duraphat fluoride varnish to permanent molars and incisors. Among children with active carious lesions, 2500 will enter the longitudinal minimally invasive treatment phase according to lesion severity: fluoride varnish for ICDAS 1-2 lesions; fluoride varnish or atraumatic restorative treatment (ART) sealants for ICDAS 3 lesions; and ART with high-viscosity glass ionomer cement for ICDAS 4-6 lesions. Participants will be re-evaluated every 3 months for up to 24 months. EXPECTED OUTCOMES: The primary outcome will be control of caries activity assessed longitudinally using ICDAS criteria. Secondary outcomes include inactivation of white spot lesions, survival of restorations and sealants and adherence to preventive measures. The study is expected to generate evidence to support public oral health policies and minimally invasive strategies for school-based caries management in Brazil. ETHICS AND DISSEMINATION: This protocol has been approved by the human research ethics committee of Universidade Metropolitana de Santos-UNIMES (protocol number: 7.630.345. Approved on 10 June 2025). Results will be submitted to international peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBER: NCT06999005 (registered on 14 May 2025).