Prevalence of dental caries lesions in Costa Rican children under 81 months living in poverty.

Dental caries remains a significant public health issue, particularly among children from low-income areas, where limited access to preventive and restorative care increases the disease burden. In Costa Rica, recent data on the prevalence of caries in children under seven years of age are lacking. This nationwide study aimed to determine the prevalence and severity of dental caries lesions in Costa Rican children aged 12-81 months living in poverty and enrolled in the Centers for Education and Nutrition and Comprehensive Child Nutrition and Care Centers (CEN-CINAI), which are national childcare and nutrition programs. A cross-sectional descriptive study was conducted with 800 children from urban and rural areas. The probability-proportional-to-size (PPS) method was used to select 40 centers, with systematic random sampling of 25 children per center. Clinical examinations were performed by eight calibrated examiners following the International Caries Detection and Assessment System (ICDAS) criteria to assess oral health conditions. The inter- and intraexaminer kappa values ranged from 0.80-0.93. The overall prevalence of caries lesions was 84.81% (ICDAS codes 1-6), with 47.19% of the participants presenting moderate-to-severe carious lesions (ICDAS codes 3-6). The highest prevalence was observed in the 37-48-month age group (91.45%). Differences in the prevalence of caries by sex were more evident in younger age groups and minimal in the older age groups. Only 28.75% of the children with caries had received restorative treatment. The 37-48-month age group presented the highest prevalence of caries, with most lesions being moderate to severe and treatment coverage remaining low.