title: Effect of 6-monthly applications of chlorhexidine varnish on incidence of occlusal caries in permanent molars: a 3-year study.
abstract: OBJECTIVE
  The aim of this study was to assess the effect of a chlorhexidine varnish on occlusal caries incidence when applied 6-monthly into the fissures of erupting and freshly erupted permanent molars.
  
  
  METHODS
  In a double-blind clinical trial, 332 children aged 5/6 and 11/12 years attending a Child Dental Health Centre were randomly assigned to a control and an experimental group. Criteria for inclusion in the study were that all first permanent molars in 5-6-year-olds and all second permanent molars in 11-12-year-olds either had recently erupted, or were in a stage of eruption, or would erupt within half a year. At baseline, counts of dmfs/DMFS and mutans streptococci in saliva were recorded. During a maximum of 3 years, every 6 months the occlusal surfaces of molars in the experimental group received a 40% chlorhexidine varnish application, whereas those in the control group received a placebo varnish application.
  
  
  RESULTS
  Data of 316 children were analysed and ANOVA showed no significant occlusal caries reduction in this sample of Dutch 5/6- and 11/12-year-old children. After stratification into low and high caries risk groups, a statistically significant caries-reducing effect on occlusal caries in permanent molars was found in the group of children with > or = 10(6) mutans streptococci per ml saliva (P < 0.05).
  
  
  CONCLUSIONS
  Six-monthly application of chlorhexidine varnish has no caries-reducing effect on occlusal caries in recently erupted permanent molars in a population with low caries prevalence.
authors.affiliation: TRIKON, Institute for Dental Clinical Research, University of Nijmegen, The Netherlands.
authors.forename: Y L
authors.initials: YL
authors.lastname: Fennis-le
authors.forename: E H
authors.initials: EH
authors.lastname: Verdonschot
authors.forename: R C
authors.initials: RC
authors.lastname: Burgersdijk
authors.forename: K G
authors.initials: KG
authors.lastname: König
authors.forename: M A
authors.initials: MA
authors.lastname: van 't Hof
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D002710:Chlorhexidine / Q000008:administration & dosage*; D015169:Colony Count, Microbial; D004245:DMF Index; D003731:Dental Caries / Q000453:epidemiology / Q000517:prevention & control*; D003750:Dental Fissures / Q000188:drug therapy; D004311:Double-Blind Method; D006801:Humans; D015994:Incidence; D007764:Lacquer; D008137:Longitudinal Studies; D008963:Molar; D009426:Netherlands / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D012044:Regression Analysis; D012463:Saliva / Q000382:microbiology; D013295:Streptococcus mutans / Q000302:isolation & purification
chemical_list: D000891:Anti-Infective Agents, Local; D002710:Chlorhexidine