title: Seven years of external control of fluoride levels in the public water supply in Bauru, São Paulo, Brazil.
abstract: Fluoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels.
  
  
  OBJECTIVE
  To report the results of seven years of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/benefit balance, whether the levels are appropriate.
  
  
  METHODS
  From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-specific electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment.
  
  
  RESULTS
  Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered "low risk" for dental fluorosis development and of "maximum benefit" for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period.
  
  
  CONCLUSIONS
  Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.
authors.affiliation: Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil. mbuzalaf@fob.usp.br
authors.forename: Marília Afonso Rabelo
authors.initials: MA
authors.lastname: Buzalaf
authors.forename: Camila Mascarenhas
authors.initials: CM
authors.lastname: Moraes
authors.forename: Kelly Polido Kaneshiro
authors.initials: KP
authors.lastname: Olympio
authors.forename: Juliano Pelim
authors.initials: JP
authors.lastname: Pessan
authors.forename: Larissa Tercília
authors.initials: LT
authors.lastname: Grizzo
authors.forename: Thelma Lopes
authors.initials: TL
authors.lastname: Silva
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Magalhães
authors.forename: Rodrigo Cardoso de
authors.initials: RC
authors.lastname: Oliveira
authors.forename: Sonia
authors.initials: S
authors.lastname: Groisman
authors.forename: Irene
authors.initials: I
authors.lastname: Ramires
mesh_terms: D001938:Brazil; D003731:Dental Caries / Q000517:prevention & control; D005457:Fluoridation / Q000706:statistics & numerical data*; D005459:Fluorides / Q000032:analysis*; D009050:Fluorosis, Dental / Q000209:etiology; D006801:Humans; D011634:Public Health; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
chemical_list: D005459:Fluorides
references.citation: J Public Health Dent. 2002 Summer;62(3):173-6
references.pmid: 12180046
references.citation: Cad Saude Publica. 2004 Mar-Apr;20(2):422-9
references.pmid: 15073621
references.citation: Rev Saude Publica. 2006 Oct;40(5):883-9
references.pmid: 17301911
references.citation: BMJ. 2000 Oct 7;321(7265):855-9
references.pmid: 11021861
references.citation: Cien Saude Colet. 2009 Jul-Aug;14(4):1261-6
references.pmid: 19721966
references.citation: J Appl Oral Sci. 2006 Oct;14(5):365-70
references.pmid: 19089059
references.citation: Community Dent Oral Epidemiol. 2002 Jun;30(3):199-209
references.pmid: 12000343
references.citation: Cad Saude Publica. 2007 May;23(5):1083-8
references.pmid: 17486231
references.citation: Cien Saude Colet. 2007 May-Jun;12(3):727-32
references.pmid: 17680130
references.citation: Crit Rev Oral Biol Med. 2002;13(2):155-70
references.pmid: 12097358
references.citation: Cad Saude Publica. 2003 Jan-Feb;19(1):61-7
references.pmid: 12700784
references.citation: J Evid Based Dent Pract. 2008 Mar;8(1):15-6
references.pmid: 18346695
references.citation: J Appl Oral Sci. 2006 Oct;14(5):346-50
references.pmid: 19089056
references.citation: Evid Based Dent. 2008;9(2):39-43
references.pmid: 18584000
references.citation: Monogr Oral Sci. 2011;22:37-51
references.pmid: 21701190
references.citation: Community Dent Oral Epidemiol. 1999 Feb;27(1):31-40
references.pmid: 10086924
references.citation: Eur J Oral Sci. 1997 Oct;105(5 Pt 2):461-5
references.pmid: 9395110
references.citation: J Dent. 2000 Aug;28(6):389-93
references.pmid: 10856802
references.citation: JAMA. 2000 Mar 8;283(10):1283-6
references.pmid: 10714718
references.citation: J Am Dent Assoc. 1985 Apr;110(4):511-3
references.pmid: 3858366
references.citation: Cad Saude Publica. 2008 Sep;24(9):2021-31
references.pmid: 18813678