title: A two-year longitudinal study of dental caries in permanent first molars of Korean elementary schoolchildren.
abstract: OBJECTIVE
  This longitudinal study investigated dental caries increment in permanent first molars of Korean elementary schoolchildren.
  
  
  METHODS
  A convenience sample of 722 children aged 7-9 years attending one urban elementary school was examined at baseline, with follow-up examinations at one and two years. Coronal surfaces of permanent first molars were scored with regard to caries experience and sealant status.
  
  
  RESULTS
  Among sound occlusal surfaces at baseline, 21 percent of upper and 25 percent of lower surfaces developed caries during the two-year interval. In teeth that erupted between baseline and the first follow-up exam, over 10 percent of occlusal surfaces developed caries. Pit and fissure caries accounted for 93 percent of all new carious surfaces, while sealants had been placed on 16 percent of occlusal surfaces during the study.
  
  
  CONCLUSIONS
  Recognizing the limitations of this convenience sample, dental sealants should be used more widely in this Korean population, and should be applied soon after tooth eruption.
authors.affiliation: Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: B K
authors.initials: BK
authors.lastname: Cho
authors.forename: H K
authors.initials: HK
authors.lastname: Kwon
authors.forename: K S
authors.initials: KS
authors.lastname: Kim
authors.forename: Y N
authors.initials: YN
authors.lastname: Kim
authors.forename: D J
authors.initials: DJ
authors.lastname: Caplan
mesh_terms: D002648:Child; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology*; D003750:Dental Fissures / Q000453:epidemiology; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008137:Longitudinal Studies; D008963:Molar; D010895:Pit and Fissure Sealants / Q000627:therapeutic use; D014078:Tooth Eruption; D014504:Urban Health / Q000706:statistics & numerical data
chemical_list: D010895:Pit and Fissure Sealants