title: Decline in dental caries among 12-year-old children in Brazil, 1980-2005.
abstract: OBJECTIVE
  This study was conducted to determine changes in values on the decayed, missing and filled teeth (DMFT) index in 12-year-old children in Brazil between 1980 and 2005, and to correlate DMFT values with human development index (HDI) values, time, population size of municipality and fluoridation of the water supply.
  
  
  METHODS
  The present study represents a retrospective ecological study using secondary data from epidemiological surveys published in indexed journals, as well as data obtained from epidemiological official surveys carried out in Brazil in 1986, 1996 and 2003, and in the State of São Paulo in 1998 and 2002. Units of study were represented by Brazilian municipalities holding average DMFT index values for 12-year-old children. Multiple regression analysis was used to examine the correlations among DMFT and HDI values, and time, population size and fluoridation of the water supply.
  
  
  RESULTS
  The final database included 550 records of DMFT values in 428 different towns. Regression analysis showed statistically significant correlations between DMFT index values and time (P < 0.001), fluoridation of the water supply (P < 0.001) and size of municipality (P < 0.001). Estimated mean DMFT index values were 8.36 in 1980, 6.08 in 1985, 4.45 in 1990, 3.29 in 1995, 2.46 in 2000 and 1.86 in 2005.
  
  
  CONCLUSIONS
  Data showed a significant decrease in dental caries across the entire country, with an average reduction of 25% occurring every 5 years. General trends indicated that a reduction in DMFT index values occurred over time, that a further reduction in DMFT index values occurred when a municipality fluoridated its water supply, and mean DMFT index values were lower in larger than in smaller municipalities.
authors.affiliation: Department of Paediatric Dentistry, University of São Paulo, Bauru, São Paulo, Brazil. jrlauris@fob.usp.br
authors.forename: José Roberto Pereira
authors.initials: JR
authors.lastname: Lauris
authors.forename: Roosevelt
authors.initials: R
authors.lastname: da Silva Bastos
authors.forename: José Roberto
authors.initials: JR
authors.lastname: de Magalhaes Bastos
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003753:Dental Health Surveys; D004522:Educational Status; D016021:Epidemiologic Studies; D005457:Fluoridation / Q000706:statistics & numerical data; D006801:Humans; D007182:Income; D008017:Life Expectancy; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D014504:Urban Health / Q000706:statistics & numerical data