Dental fluorosis in upper permanent incisors of public schoolchildren in Rio de Janeiro, Brazil

Objective To assess the prevalence and severity of dental fluorosis in chil dren aged 7 to 12. Methods The study population comprised 266 children aged 7 to 12 years, enr olled in a public school in the city of Rio de Janeiro, Brazil, selected us ing a simple random sample method. All examinations were carried out betwee n August and December 1999 by a single trained and calibrated examiner (Kap pa = 0.92). After obtaining their parents' consent the children had their u pper permanent incisors examined under natural light. Their teeth were prev iously cleaned and dried with cotton rolls. The differential diagnosis betw een milder forms of dental fluorosis and nonfluoride enamel opacities was m ade according to Russel's diagnostic criteria. The severity of fluorosis wa s assessed by the Thylstrup and Fejerskov Index (TF). Results The prevalence of dental fluorosis was 7.9% (CI 95%, 5.0-11.8). The severity ranged from 1 to 3 and 77% of the affected teeth had a TF score o f 1. Conclusion These results suggest that dental fluorosis does not represent a public health problem in this population.