title: Caries and fluorosis in 6- and 9-year-old children residing in three communities in Iran.
abstract: OBJECTIVE
  The aim of this study was to investigate the caries and fluorosis prevalence among 6- and 9-year-old students in three communities in Iran with varying urbanization and fluoride in piped water.
  
  
  METHODS
  Data were obtained from 523 dental examinations of 6- and 9-year olds in an upper middle class district in Teheran (T) (0.3 mg F/l), the city of Semnan (S) (1.3 mg F/l), and the village Dibaj (D) (0.2 mg F/l).
  
  
  RESULTS
  Children in the naturally fluoridated town showed slightly higher dmfs/dfs (SD) values for both 6-year olds [S: 9.1 (9.2), T: 7.2 (7.4), D: 7.1 (6.1)] and 9-year olds [S: 6.0 (6.2), T: 4.4 (4.2), D: 5.0 (4.7)], whereas the mean dmft/dft values as well as the numbers of caries-free children were comparable. A lower prevalence of dental restorations was reported for both Semnan and Dibaj compared with Teheran. A higher prevalence of fluorosis [Tooth Surface Index of Dental Fluorosis (TSIF) 3-7] was observed in the naturally fluoridated town compared with the low-fluoridated communities.
  
  
  CONCLUSIONS
  The ingestion of naturally fluoridated water (1.3 mg F/l) seemed to have a negligible effect on caries prevalence, but resulted in higher prevalence of dental fluorosis. It is emphasized that the study population was not adjusted for socioeconomic status, availability of dental care nor for exposures to other sources of fluoride. Nevertheless, it can be concluded that caries prevalence in Iran is quite low compared with that in other countries in the Middle East and that the elevated fluoride levels in the drinking water in Semnan may contribute to the development of mild to severe fluorosis.
authors.affiliation: Department of Operative Dentistry and Periodontology, School of Dental Medicine, Charité - Universitätsmedizin Berlin, Germany. hendrik.meyer-lueckel@charite.de
authors.forename: H
authors.initials: H
authors.lastname: Meyer-Lueckel
authors.forename: S
authors.initials: S
authors.lastname: Paris
authors.forename: B
authors.initials: B
authors.lastname: Shirkhani
authors.forename: W
authors.initials: W
authors.lastname: Hopfenmuller
authors.forename: A M
authors.initials: AM
authors.lastname: Kielbassa
mesh_terms: D002648:Child; D003430:Cross-Sectional Studies; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D005260:Female; D005457:Fluoridation / Q000706:statistics & numerical data; D009050:Fluorosis, Dental / Q000453:epidemiology*; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008963:Molar / Q000473:pathology; D015995:Prevalence; D012423:Rural Health / Q000706:statistics & numerical data; D012923:Social Class; D014094:Tooth, Deciduous / Q000473:pathology; D014504:Urban Health / Q000706:statistics & numerical data; D014507:Urbanization