Objective: To determine the prevalence and severity of enamel fluorosis in the permanent dentition of children aged 6-9 years old exposed to fluoride through a milk fluoridation programme in Codegua, Chile.
Basic research design: A survey was conducted in 2002 of a sample of school children living in Codegua (n = 215) and La Punta, the control community (n = 206) to compare enamel fluorosis data with those obtained in 1994. Dean's criteria were followed to assess enamel fluorosis.
Results: It was found that 16.4% of the children aged 6-9 years from Codegua had questionable fluorosis in 2002, while in 1999 10.3% were classified in this category. In addition, 7.9% and 1.3% of the children in 2002 and 1994, respectively, had at least very mild fluorosis. These increments were not observed in the control community. Comparison of mean community fluorosis indices (CFI) between the children in 2002 (CFI = 0.18) and those in 1994 (CFI = 0.06) was found to be significant (p < 0.001). For La Punta, no statistically significant results were observed (CFI 0.16 vs. 0.15).
Conclusions: Present results indicate that, although there was an expected increase in the prevalence and severity of enamel fluorosis after four years of fluoride exposure, the CFI for Codegua in 2002 is well below the upper limit of the CFI range associated with a public health concern. Therefore, if the average daily fluoride ingestion was adjusted to more appropriate doses at the time of mineralisation of anterior permanent teeth, this would minimise the increase in the prevalence of enamel fluorosis without loosing the dental caries preventive effect of F.