Fluorose dentária em escolares de 12 e 15 anos de idade. Salvador, Bahia, Brasil, nos anos 2001 e 2004

This article compares the results of two surveys in Salvador, Bahia State, Brazil, on prevalence and severity of dental fluorosis in 12 and 15-year-olds. The article discusses the survey methodologies in relation to their sampling process, calibration of examiners, and data collection procedures, comparing the resulting differences using chi-square and 95% confidence intervals obtained with the Dean index. A total of 3,313 adolescents 12 and 15 years of age were analyzed in 2001 and 1,032 in 2004. Both surveys used examiner calibration, and the samples were population-based. In the second survey there were a higher proportion of students from public schools for both ages, as compared to 2001 (p < 0.001). There was no significant difference in the fluorosis rate at 12 years, with a prevalence of 32.64% in 2004 and 31.4% in 2001. For 15-year-olds, the prevalence in 2004 (16.83%) was lower than in 2001 (27.6%). No increase was observed in the prevalence or severity of fluorosis in Salvador from 2001 to 2004.