Abstract
INTRODUCTION: Early childhood caries (ECC) continues to be a public health problem. The application of silver diamine fluoride (SDF) is a simple, non-invasive procedure. This study aims to evaluate SDF's effectiveness, acceptability and oral health-related quality of life (OHRQoL) compared with atraumatic restorative treatment in managing ECC. METHODS AND ANALYSIS: An open-label parallel superiority randomised clinical trial will be conducted involving children aged 2-5 years. Participants will include children with at least one active cavitated lesion (ICDAS 5+) of their primary teeth, with no signs of pulp involvement. The trial will occur at preschools in the La Araucanía and Metropolitan Regions of Chile from 2025 to 2027. The primary outcome variable will be the caries lesion arrest, acceptability and OHRQoL. We will also determine the presence of any adverse effects. Evaluations will be carried out at 6 and 12 months. A sample of 234 teeth with carious lesions per group is estimated. The primary inferential analysis will be performed on an intention-to-treat basis; a per-protocol analysis will be conducted for adverse effects. For caries lesion arrest, a multilevel logistic regression model adjusted for significant covariates will be used to account for within-child clustering. The acceptability will be assessed through quantitative and qualitative methods. The magnitude of change in OHRQoL between baseline and follow-up will be quantified using effect size estimates derived from the early childhood health impact scale survey data. ETHICS AND DISSEMINATION: This study's implementation benefits the study population, and the ethical principles of research have been considered and approved by the Science Committee of the University, Resolution N°049_19. The results and conclusions of the clinical trial will be published in academic conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT06786975.