Prevalence of hypomineralized second primary molars and association with socioeconomic characteristics and dental caries in a Brazilian population of preschoolers: a cross-sectional study.

Objective: To analyze the prevalence of hypomineralized second primary molar (HSPM) and its association with socioeconomic characteristics and dental caries in a Brazilian population of preschoolers.

Material and methods: 603 preschoolers, enrolled in public preschools in Itajaí (state of Santa Catarina, Brazil), took part in the study. To assess the participants' socio-economic characteristics, an original questionnaire was formulated and sent to the children's parents. The clinical evaluation was carried out by a calibrated examiner using the deft/DMFT index for dental caries and Ghanim et al. (Ghanim et al., Eur Arch Paediatr Dent, 2015) criteria for HSPM. The data were analyzed through Poisson regression, using STATA statistical software, and the association analyses were presented by prevalence ratios (PR).

Results: The prevalence of at least one HSPM-affected second molar was 24.5%. The prevalence of HSPM was associated to the city's geographical regions of the Educational hubs (p < 0.001). A significant association was found between dental caries and HSPM (p = 0.003; PR: 1.31; 95% CI 1.09-1.56). Children with HSPM were 31% more likely to experience dental caries than children without HSPM. Geographical regions of educational hubs were also significantly associated with HSPM (p < 0.001). None of the socioeconomic characteristics was associated with HSPM (p > 0.05).

Conclusion: HSPM is a common developmental defect of enamel in children in our study. The HSPM distribution was associated with the city's geographic regions. Children with HSPM are more likely to experience dental caries. Socioeconomic characteristics were not associated with HSPM.