title: Root-filled teeth and recurrent caries-a study of three repeated cross-sectional samples from the city of Jönköping, Sweden.
abstract: OBJECTIVE
  The aim of the study was to test the hypothesis that root-filled teeth are at a higher caries risk than non-root-filled teeth.
  
  
  METHODS
  Two sub-samples from epidemiologically obtained data collected in 1983, 1993 and 2003 in the city of Jönköping, Sweden, were analysed. All the participants were examined clinically and radiographically and the type of filling and the presence or absence of caries were recorded. Sub-sample 1 comprised 832 individuals (9202 teeth) aged 20-70 years with at least eight premolars/molars. In sub-sample 2, 163 subjects (577 teeth) with only one or two decayed tooth surfaces and at least one tooth with full crown coverage were analysed.
  
  
  RESULTS
  Logistic regression analysis found that root-filled teeth were predictive of recurrent caries when controlling for the type of restoration in sub-sample 1 (OR = 1.68; 1.41-2.0; CI 95%) and sub-sample 2 (OR = 2.20; 1.07-4.52; CI 95%).
  
  
  CONCLUSIONS
  In support of the suggested hypothesis, the data revealed a significant association between root-filled teeth and recurrent caries.
authors.affiliation: Institute of Postgraduate Dental Education, Jönköping, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Frisk
authors.forename: Khalid
authors.initials: K
authors.lastname: Merdad
authors.forename: Claes
authors.initials: C
authors.lastname: Reit
authors.forename: Anders
authors.initials: A
authors.lastname: Hugoson
authors.forename: Dowen
authors.initials: D
authors.lastname: Birkhed
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003442:Crowns / Q000706:statistics & numerical data; D003731:Dental Caries / Q000453:epidemiology*; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D005544:Forecasting; D006801:Humans; D008875:Middle Aged; D016300:Radiography, Bitewing / Q000706:statistics & numerical data; D011862:Radiography, Panoramic / Q000706:statistics & numerical data; D012008:Recurrence; D018570:Risk Assessment; D012390:Root Canal Therapy / Q000706:statistics & numerical data*; D013548:Sweden / Q000453:epidemiology; D019553:Tooth, Nonvital / Q000453:epidemiology; D055815:Young Adult