ABSTRACT
OBJECTIVE: To investigate protection or risk factors for dental fluorosis in permanent teeth of 6 to 8 year-old children in a neighborhood of Fortaleza, Brazil. METHODS: This case-control study included 57 controls and 67 children with fluorosis affecting superior and inferior incisors teeth as determined by the Dean classification criteria. Presence of fluorosis was considered as the dependent variable. Data concerning independent variables were obtained through interviews with the parents. Fisher's exact test was used to determine associations between fluorosis and the independent variables. Odds ratios (OR) were calculated to investigate associations and likelihood of fluorosis in the case group, with 95% significance level. RESULTS: Fluorosis was significantly associated with type of housing (owned, rented or squatted), but not with the source of drinking water or use of fluoridated toothpaste and fluoride supplements. Univariate analysis showed that the risk of fluorosis was higher in children who began drinking powdered milk mixed with water before 2 years of age (OR = 4.53; IC95%: 1.07-26.74) and in those who did not breastfeed (OR = 6.66; IC95%: 1.61-38.62). In the multivariate analysis, only breastfeeding was associated with fluorosis (4.54; IC95%: 1.21-16.66). CONCLUSIONS: Breastfeeding was a protection factor against fluorosis. More specific categorization criteria must be established to investigate relationships between fluorosis and socioeconomic class.