Resumen

Objective: To determine the experience, prevalence and severity of dental caries, as well as the Significant Caries Index (SiC) and the treatment needs (TN) in schoolchildren aged six to twelve years. Additionally, to estimate the effect of having caries in the primary dentition on the subsequent caries experience in the permanent dentition. Material and methods: A cross-sectional study was undertaken in 3865 schoolchildren from San Luis Potosí City, Mexico. Subjects were clinically evaluated by three standardized examiners (kappa > 0.85) using the WHO.s criteria for primary (dmft) and permanent (DMFT) dentitions. In the statistical analyzes non-parametric test and logistic regression were used. Results: Mean age was 8.69 + 1.79, and 51.3% were women. In the primary dentition: dmft index was 1.88 + 2.34 and the caries prevalence (dmft > 0) of 56.8%. For severity 22.0% and 5.6% had dmft > 3 and dmft > 6, respectively. In six year olds, caries prevalence was 56.0% and SiC 5.45. In the permanent dentition: DMFT index was 1.11 + 2.03 and the caries prevalence (DMFT > 0) of 36.8%. For severity 11.8% and 2.8% had DMFT > 3 and DMFT > 6, respectively. In twelve year olds, the DMFT index was 4.14 + 4.15 and the SiC 9.15. The TN index was 88.5% for primary dentition and 93.6% for the permanent. In logistic regression we observed that associated to caries prevalence in permanent dentition was presence of caries in primary dentition (OR = 6.37; p < 0.001), female sex (OR = 1.33; p < 0.001) and older age (OR = 1.69; p < 0.001). Conclusions: Caries prevalence in six year olds and DMFT index in twelve year olds were higher than values established by WHO. Caries severity in the primary dentition was twice than the level observed in the permanent dentition. High TN in both dentitions was evident. Presence of caries in the primary dentition was a strong risk indicator for caries in permanent dentition.