RESUMO
OBJECTIVES: To evaluate whether characteristics related to mother's oral health, trajectory of family income, and maternal education are associated with the incidence of caries in dentin in preschool children. MATERIALS AND METHODS: One hundred fifty-eight mothers and their children were evaluated at baseline and re-evaluated after 3 years. Sociodemographic variables, dental caries, and biofilm of the mothers and children and daily sugar intake of the children were evaluated. Poisson regression was used to evaluate what factor represents risk for the incidence of caries in dentin at four to 6 years of age. RESULTS: The risk of the incidence of caries in dentin was 54% higher in children whose mothers had a low level of education at both baseline and follow-up. Children from families with an income lower at baseline and follow-up (RR 2.49; 95% CI 1.62-3.83) and those whose families experienced a reduction in income in this period (RR 2.05; 95% CI 1.29-3.26) had a greater risk of the incidence of caries in dentin. Moreover, children who increased their daily sugar intake (RR 1.67; 95% CI 1.09-2.52), those that maintained high sugar intake (RR 1.81; 95% CI 1.14-2.87), and those with cavitated caries at baseline (RR 1.53; 95% CI 1.19-1.97) had a greater risk of the incidence of caries in dentin. CONCLUSIONS: Low mother's education, a lower family income, a reduction in family income, a high frequency of daily sugar intake, and a history of cavitated caries were risk factors for the incidence of caries in dentin. CLINICAL RELEVANCE: The results could help in the targeting of improved prevention and control strategies for dental caries.