title: Dental fluorosis in children in areas with fluoride-polluted air, high-fluoride water, and low-fluoride water as well as low-fluoride air: a study of deciduous and permanent teeth in the Shaanxi province, China.
abstract: OBJECTIVE
  The aim of the study was to assess dental fluorosis (DF) in the deciduous and permanent teeth of children in areas with high-F coal (area A) and high-F water (area C) compared to children from area B, with low-F water and coal.
  
  
  METHODS
  596 children were examined. DF was assessed by TF-score. F-content of indoor air, drinking water, coal, tea, rice, and maize was analyzed.
  
  
  RESULTS
  F-content of air and coal ranged from 3.2 microg/m(3) and 25.8 mg/kg (area B), 3.8 microg/m(3) and 36.3 mg/kg (area C) to 56.8 microg/m(3) and 713.1 mg/kg (area A). Likewise, mean F-content of water ranged from approximately 0.50 mg/l (areas A and B) to 3.64 mg/l (area C). F-content of tea leaves was similar in all three areas. Maize and rice contained <5 mg F/kg. Prevalence of primary teeth with DF was 49.1%, 2.0%, and 66.8% in areas A, B, and C, respectively. Similarly, DF was found in 96.7% (area A), 19.6% (area B), and 94.4% (area C) of the permanent teeth. Severe fluorosis (TF > or = 5) was found in area A (47.0%) and area C (36.1%) (p<0.01). Early erupting teeth had slightly higher mean TF-scores in area A than in area C.
  
  
  CONCLUSIONS
  DF was prevalent in both dentitions in areas A and C. Similarity in percentages of DF may indicate that indoor air with approximately 60 microg F/m(3) and drinking water with 3.6 mg F/L are similarly toxic to developing permanent teeth. The percentage of deciduous teeth with DF was significantly lower in area A compared to area C. Where low-F coal and low-F water were used (area B), approximately 20% of permanent teeth had DF, indicating a relatively low tolerance to fluoride in Chinese children brought up under the present living conditions.
authors: Department of Oral Science, Faculty of Dentistry, University of Bergen, Norway. jianping_ruan@hotmail.com
authors: Jian Ping
authors: JP
authors: Ruan
authors: Asgeir
authors: A
authors: Bårdsen
authors: Anne Nordrehaug
authors: AN
authors: Astrøm
authors: Rui Zhe
authors: RZ
authors: Huang
authors: Zhi Lun
authors: ZL
authors: Wang
authors: Kjell
authors: K
authors: Bjorvatn
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000633:toxicity*; D002648:Child; D002681:China / Q000453:epidemiology; D003031:Coal / Q000009:adverse effects; D019229:Dentition, Permanent; D009050:Fluorosis, Dental / Q000453:epidemiology / Q000209:etiology*; D005506:Food Contamination; D006801:Humans; D015995:Prevalence; D013662:Tea / Q000737:chemistry; D014094:Tooth, Deciduous / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D000393:Air Pollutants; D003031:Coal; D013662:Tea; D014874:Water Pollutants, Chemical