In Ecuador, national data on dental caries are scarce and the detection of incipient enamel lesions has been omitted. The objective of this study was to determine the prevalence of caries in school children aged 6 and 12 years of both sexes, belonging to urban and rural areas of three provinces of the country, using the International Caries Detection and Assessment System (ICDAS II). The sample consisted of 665 children from public schools, examined according to ICDASII. Caries prevalence and caries index were established using ICDAS II 2-6/C-G and ICDAS II 4-6/E-G criteria for comparison with WHO indicators. The Mann–Whitney U statistical test was used for comparison of two groups, the effect size was measured with the correlation coefficient. and the Kruskal–Wallis H test (p < 0.05) for multiple comparisons. Caries prevalence exceeded 87% for primary and permanent dentition. There were no significant differences according to province (p ≤ 0.05). The caries index at 6 years was 6.57 and at 12 years 9.21. The SIC was high at 12 years in rural areas. The prevalence of caries in the population studied was high despite the preventive measures established by health agencies.

Developmental defects of enamel (DDEs) are widely observed in children and are related to the appearance of dental caries, malocclusion, tooth sensitivity, and unfavorable esthetic conditions. The objective of this cross-sectional study was to determine the prevalence and distribution of enamel defects present in children aged 6 to 12 years in the provinces located in southern Ecuador. A total of 1606 schoolchildren were examined under the World Health Organization criteria for diagnosis of DDEs. The results are presented using percentage frequency measures and chi-square associations. Some types of DDEs were presented by 50% of the schoolchildren, mainly diffuse opacity, with no statistical differences according to place of residence and/or environment, sex, and age (p > 0.05). In Ecuador, it is necessary to carry out studies on the factors that trigger enamel defects, since they may be associated with the high prevalence of caries already reported in other studies in the country.