Prevalence of enamel fluorosis in 12-year-olds in two Swiss cantons.

The neighbouring cantons Basel-Stadt and Basel-Landschaft had introduced different fluoridation schemes for caries prevention: Basel-Stadt provided drinking water fluoridated at 0.8-1 ppm F since 1962, while Basel-Landschaft introduced fluoridated domestic salt (250 ppm F since 1983). Representative samples of 12-year-old schoolchildren (6th-graders) were studied to evaluate the prevalence of (I) dental fluorosis (FOP) using the Thylstrup-Fejerskov (TF) index, (II) non fluoride-associated enamel opacities (non-FOP), and (III) hypoplasia of the incisors.