title: Caries incidence in permanent first molars after discontinuation of a school-based chlorhexidine-thymol varnish program.
abstract: OBJECTIVE
  To determine whether the cessation for 3 years of a 24-month program of chlorhexidine-thymol varnish applications would affect caries incidence in the first permanent molars of a population of schoolchildren of middle and lower-middle socioeconomic level.
  
  
  METHODS
  Two groups of 6-7-year-old schoolchildren, randomized by school-class, were followed up in a clinical trial. One group received applications of chlorhexidine-thymol varnish every 3 months and the other group acted as controls. The program ended after 24 months and its effects were evaluated. Three years later, 55.5% of the schoolchildren were re-examined and the caries increments were documented.
  
  
  RESULTS
  At the end of the 24-month program, the treated children had significantly fewer decayed and filled surfaces in permanent molars (lower DFS index) versus the controls. At 3 years after the discontinuation of the program, this difference had disappeared; there were no differences in the incidence of decayed, missing and filled surfaces (DMFS) index in permanent molars between the treated children and the controls.
  
  
  CONCLUSIONS
  The cessation for 3 years of a 3-month program of chlorhexidine-thymol varnish applications resulted in a nonsignificant increase in the prevalence of dental caries in the permanent first molar.
authors.affiliation: Department of Preventive Dentistry, School of Dentistry, University of Granada, Granada, Spain. pbaca@ugr.es
authors.forename: Pilar
authors.initials: P
authors.lastname: Baca
authors.forename: Pilar
authors.initials: P
authors.lastname: Junco
authors.forename: Manuel
authors.initials: M
authors.lastname: Bravo
authors.forename: Adela P
authors.initials: AP
authors.lastname: Baca
authors.forename: M José
authors.initials: MJ
authors.lastname: Muñoz
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D004245:DMF Index; D003731:Dental Caries / Q000517:prevention & control*; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007764:Lacquer; D008297:Male; D008963:Molar / Q000473:pathology*; D012571:School Dentistry; D016037:Single-Blind Method; D012923:Social Class; D018709:Statistics, Nonparametric; D013943:Thymol / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D000891:Anti-Infective Agents, Local; D004338:Drug Combinations; C079161:chlorhexidine, thymol drug combination; D013943:Thymol; D002710:Chlorhexidine