title: A population-based observational study of dental caries among survivors of childhood cancer.
abstract: BACKGROUND
  The few published studies on caries among childhood cancer survivors are small and their results are conflicting. The study aim was to examine the risk of dental caries among children who have survived cancer.
  
  
  METHODS
  We included 299,426 7-year-old, 313,461 12-year-old, and 301,930 15-year-old children born between 1984 and 1988 in a nationwide population-based study linking records from Danish Cancer Registry with records from the national database on oral health. Children whose dental examinations had been preceded by a cancer diagnosis (288 7-year-old, 459 12-year-old, and 526 15-year-old) were compared with children without cancer according to presence of caries: caries-free children; children with any caries experience; and children with severe caries experience (i.e., caries in one or more smooth tooth surface).
  
  
  RESULTS
  Children diagnosed with cancer before the age of 5 years did not have increased caries prevalence in permanent teeth at ages 12; and 15. Children diagnosed with cancer between 5 and 6 years of age had an increased prevalence of severe caries at age 12 years (prevalence ratio (PR) = 1.59 (95% CI: 1.09-2.31; P = 0.02)), but this difference disappeared by age 15. For children diagnosed with cancer at 5 or 6 years of age and who received radiation therapy the PR of severe caries was 1.52 (95% CI: 0.97-2.37; P = 0.07), 2.13 (95% CI: 0.89-5.10; P = 0.09), and 0.31 (95% CI: 0.07-1.45; P = 0.13) at ages seven, 12 and 15 years respectively.
  
  
  CONCLUSIONS
  Cancer and cancer treatment during childhood are risk factors for caries.
authors.affiliation: Department of Community Oral Health and Pediatric Dentistry, School of Dentistry, Faculty of Health Sciences, Aarhus University, Aarhus, Denmark. pia.wogelius@rn.dk
authors.forename: Pia
authors.initials: P
authors.lastname: Wogelius
authors.forename: Göran
authors.initials: G
authors.lastname: Dahllöf
authors.forename: Anders
authors.initials: A
authors.lastname: Gorst-Rasmussen
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
authors.forename: Steen
authors.initials: S
authors.lastname: Rosthøj
authors.forename: Sven
authors.initials: S
authors.lastname: Poulsen
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003718:Denmark / Q000453:epidemiology; D003731:Dental Caries / Q000150:complications / Q000453:epidemiology*; D006801:Humans; D009369:Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000532:radiotherapy; D015995:Prevalence; D012042:Registries