title: Caries risk analysis: considering caries as an individual time-dependent process.
abstract: OBJECTIVE
  To estimate the probability that a tooth does not develop a cavitated lesion (= end-stage caries) within time periods of interest. Additionally it was of interest to assess the heterogeneity between patients, in relation to the time periods required for their teeth to develop a cavitated lesion.
  
  
  METHODS
  A prospective study using patient data of a clinical pedodontic course.
  
  
  METHODS
  Forty-one patients who had been followed for at least 3 years were selected. Before initiation of therapy, affiliation to a specific risk group was checked. Nine individuals who had belonged to a high-risk group on test were excluded. Of 1968 teeth, 1378 were eligible for data evaluation. The statistical techniques applied originate from time-to-event analysis methods, including a parametric frailty approach providing estimates of the relative caries risk for each individual to develop a cavitated lesion.
  
  
  RESULTS
  In the selected group of patients the probability that a tooth remained free of a cavitated lesion within five years ranged from 0.89 to 0.95 applying a 95% confidence interval. In the present sample the true caries risk of the patients to develop a cavitated lesion varied considerably although such variation was not expected from the individual examinations at baseline.
  
  
  CONCLUSIONS
  The frailty model accounts sufficiently for the heterogeneity of each patient. The applied time-to-event methods facilitated reliable estimation of both the probability that a tooth remains free of a cavitated lesion within a certain time and the relative caries risk of an individual to develop a cavitated lesion.
authors.affiliation: Faculty of Dentistry, Department of Conservative Dentistry, University of Tübingen, Tübingen, Germany. matthias.kalwitzki@med.uni-tuebingen.de
authors.forename: M
authors.initials: M
authors.lastname: Kalwitzki
authors.forename: R
authors.initials: R
authors.lastname: Weiger
authors.forename: D
authors.initials: D
authors.lastname: Axmann-Krcmar
authors.forename: R
authors.initials: R
authors.lastname: Rosendahl
mesh_terms: D002648:Child; D002675:Child, Preschool; D004245:DMF Index; D003625:Data Collection; D003731:Dental Caries / Q000453:epidemiology*; D005163:Factor Analysis, Statistical; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D015233:Models, Statistical; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D013997:Time Factors