title: Caries reductions between 1995, 1997 and 1999 in preschool children in Diadema, Brazil.
abstract: OBJECTIVE
  This study aimed to assess changes in caries prevalence and severity in preschool children in Diadema, Brazil.
  
  
  METHODS
  Three cross-sectional surveys were conducted, using the same protocol, in 1995, 1997 and 1999. The first survey included children aged 5-35 months, and the second and third, children aged 5-59 months. Participants were selected from all children attending a National Day of Children's Vaccination; 548, 992 and 690 in 1995, 1997 and 1999, respectively. This approach was sound as uptake rates for all years studied were above 90% for children aged between 1 and 59 months in all three surveys. Caries experience was measured using the World Health Organization (WHO) def index. Time-lag and quasi-longitudinal analysis were carried out.
  
  
  RESULTS
  Time-lag analysis showed a marked and statistically significant decline in the prevalence and severity of coronal and rampant caries between 1995 and 1999. There were reductions of 36.5% in the prevalence of caries in 2-year-olds between 1995 and 1997 (P < 0.002) and 36.0% between 1997 and 1999 (P = 0.041). The mean def-s at the same age decreased from 2.0 in 1995 to 1.1 in 1997 (P < 0.001) and to 1.0 in 1999 (P > 0.05). The quasi-longitudinal analysis showed a statistically significantly increase in the percentage of children with caries between 1995 and 1997 and 1997 and 1999 (P < 0.001), but not for 2-year-old children between 1995 and 1997 (P > 0.05). The same pattern was observed for severity of dental caries.
  
  
  CONCLUSIONS
  Oral health in preschool children in Diadema improved markedly during 1995-99.
authors.affiliation: Department of Paediatric Dentistry, Universidade de São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Bönecker
authors.forename: W
authors.initials: W
authors.lastname: Marcenes
authors.forename: A
authors.initials: A
authors.lastname: Sheiham
mesh_terms: D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D016009:Chi-Square Distribution; D002675:Child, Preschool; D015331:Cohort Studies; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D018709:Statistics, Nonparametric