Dental caries is the most prevalent chronic condition among Argentine children, with distribution and severity strongly shaped by social and territorial inequalities. This study evaluated caries treatment needs and their spatial and socio-economic associations among preschool children in Buenos Aires.

An ecological population study was conducted among 54 337 6-year-old children attending public schools in Buenos Aires. Caries severity was measured using the Caries Treatment Needs Index (CTNI) by calibrated examiners.

Socio-economic indicators included individual health coverage, neighbourhood housing prices, distance to the nearest primary health centre, population density and the proportion of households with unsatisfied basic needs. Analyses comprised descriptive statistics, multivariate regression, ORs and spatial autoregressive models.

Overall, 67.9% of children had treatment needs (CTNI >2) and 17.5% had high needs (CTNI >10), with significant heterogeneity across municipalities (p

Caries treatment needs in Buenos Aires follow a clear socio-economic and spatial gradient, with both individual and neighbourhood disadvantage independently associated with increased needs and highlighting the need for targeted, territorially focused public health strategies.