title: Relationship between caries prevalence and incidence among adolescents.
abstract: The purpose of this study was 1) to determine the strength and direction of the association between caries prevalence at 13-14 years of age and subsequent caries increments and 2) to assess the goodness of fit of a multivariate model to caries increments from age 13 1/2 to 20. Two sets of data were used. The first consisted of treatment records for 114 children from an incremental dental care program. They were divided into high and low caries prevalence groups at ages 13 and 14 and 2-and 3-year caries increments were calculated. Unstandardized regression coefficients and Pearson's r were used to determine the relationship between baseline caries prevalence and subsequent caries increments. This relationship was consistently positive in the low prevalence group, but changed to negative in the high prevalence group. This change of direction is most likely attributable to saturation with regard to caries. The second material comprised 20-year-old military recruits for 90 of whom treatment records were available from age 13 1/2. Caries prevalence at 13 1/2 years of age was by far the most important predictor of caries increment from age 13 1/2 to 20. The multivariate model provided a good fit to the empirical data (R2 = 37.4%). It was concluded that the interpretation of the results of clinical and field trials of anticaries agents may be complicated due to a saturation phenomenon if adolescent subjects with high caries prevalence of baseline are used.
mesh_terms: D000293:Adolescent; D000328:Adult; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008885:Military Dentistry; D008954:Models, Biological; D009664:Norway; D012189:Retrospective Studies