Family income modifies the association between frequent sugar intake and dental caries.

AIM: The aim of this cross-sectional study was to investigate whether family income modifies associations between dental caries and sex, age, mother's education, type of preschool, sugar intake, and toothbrushing. BACKGROUND: Dental caries is a multifactorial dyanamic disease primarily mediated by biofilm and sugar. DESIGN: A randomly selected sample of 308 Brazilian preschool children aged 1-3 years underwent a clinical oral examination for the assessment of moderate/extensive dental caries using codes 3-6 of the International Caries Detection and Assessment System. Mothers were asked to fill out a form addressing the child's demographic and socioeconomic characteristics as well as the frequency of sugar intake. Statistical analysis involved descriptive statistics, the chi-squared test, and Poisson regression models. RESULTS: The prevalence of moderate/extensive dental caries was 42.5%. The adjusted model revealed that within low-income families (<2 times the monthly minimum wage), the prevalence of dental caries was higher among children with a high frequency of sugar intake (>/= twice per day) than in those with a low frequency of sugar intake (< twice a day) (RR = 1.79; CI: 1.38-2.33). In families with higher income (>/=2 times the monthly wage), no significant association between sugar intake and dental caries was, however, found. CONCLUSIONS: In conclusion, monthly family income can modify the association between the high frequency of sugar intake and dental caries.