title: Measuring the short-term impact of fluoridation cessation on dental caries in Grade 2 children using tooth surface indices.
abstract: OBJECTIVE
  To examine the short-term impact of fluoridation cessation on children's caries experience measured by tooth surfaces. If there is an adverse short-term effect of cessation, it should be apparent when we focus on smooth tooth surfaces, where fluoride is most likely to have an impact for the age group and time frame considered in this study.
  
  
  METHODS
  We examined data from population-based samples of school children (Grade 2) in two similar cities in the province of Alberta, Canada: Calgary, where cessation occurred in May 2011 and Edmonton where fluoridation remains in place. We analysed change over time (2004/2005 to 2013/2014) in summary data for primary (defs) and permanent (DMFS) teeth for Calgary and Edmonton, for all tooth surfaces and smooth surfaces only. We also considered, for 2013/2014 only, the exposed subsample defined as lifelong residents who reported usually drinking tap water.
  
  
  RESULTS
  We observed, across the full sample, an increase in primary tooth decay (mean defs - all surfaces and smooth surfaces) in both cities, but the magnitude of the increase was greater in Calgary (F-cessation) than in Edmonton (F-continued). For permanent tooth decay, when focusing on smooth surfaces among those affected (those with DMFS>0), we observed a non-significant trend towards an increase in Calgary (F-cessation) that was not apparent in Edmonton (F-continued).
  
  
  CONCLUSIONS
  Trends observed for primary teeth were consistent with an adverse effect of fluoridation cessation on children's tooth decay, 2.5-3 years post-cessation. Trends for permanent teeth hinted at early indication of an adverse effect. It is important that future data collection efforts in the two cities be undertaken, to permit continued monitoring of these trends.
authors.affiliation: Department of Community Health Sciences and O'Brien Institute for Public Health, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Lindsay
authors.initials: L
authors.lastname: McLaren
authors.affiliation: School of Dentistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Steven
authors.initials: S
authors.lastname: Patterson
authors.affiliation: Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Salima
authors.initials: S
authors.lastname: Thawer
authors.affiliation: Research Facilitation, Research Priorities and Implementation, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Peter
authors.initials: P
authors.lastname: Faris
authors.affiliation: Research and Innovation, Surveillance and Infrastructure, Population Public and Aboriginal Health, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Deborah
authors.initials: D
authors.lastname: McNeil
authors.affiliation: Alberta Cancer Prevention Legacy Fund, Population Public and Aboriginal Health, Alberta Health Services and Department of Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Melissa
authors.initials: M
authors.lastname: Potestio
authors.affiliation: Formerly: Provincial Oral Health Office, Alberta Health Services, Calgary, Alberta, Canada.
authors.forename: Luke
authors.initials: L
authors.lastname: Shwart
mesh_terms: D000416:Alberta / Q000453:epidemiology; D002648:Child; D003731:Dental Caries / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D005457:Fluoridation; D006801:Humans
keywords: Public health; fluoridation