title: Effect of eucalyptus-extract chewing gum on oral malodor: a double-masked, randomized trial.
abstract: BACKGROUND
  Eucalyptus extracts were found to possess an antibacterial activity against some oral pathogens that produce oral malodor compounds in vitro; however, the clinical effects with respect to oral malodor in humans remain unproven. In the present investigation, a randomized clinical study was designed to test the hypothesis that eucalyptus-extract chewing gum can reduce oral malodor in the general adult population.
  
  
  METHODS
  Subjects were randomly assigned to the following three groups: a high-concentration (0.6% eucalyptus extract) group (n = 32), a low-concentration (0.4% eucalyptus extract) group (n = 32), and a placebo group (n = 33). The intake period was 12 weeks. The organoleptic score, level of volatile sulfur compounds (VSCs), and tongue-coating score were recorded at baseline and 4, 8, 12, and 14 weeks. Treatment-to-time interactions among groups were evaluated by repeated-measures analysis of variance (ANOVA) followed by the Games-Howell pairwise comparison test.
  
  
  RESULTS
  Relative to baseline readings, significant reductions in clinical parameters, including organoleptic and tongue-coating scores in the high- and/or low-concentration groups, occurred at 4, 8, 12, and 14 weeks (P <0.05). In addition, group-time interactions revealed significant reductions in the organoleptic score, VSCs, and tongue-coating score in both concentration groups compared to the placebo group (P <0.05).
  
  
  CONCLUSIONS
  Eucalyptus-extract chewing gum had long-term effects on the olganoleptic score, levels of VSCs, and tongue-coating score. These findings suggest that eucalyptus-extract chewing gum may reduce oral malodor by decreasing the accumulation of tongue coating.
authors.affiliation: Department of Preventive Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan. tanakam@dent.osaka-u.ac.jp
authors.forename: Muneo
authors.initials: M
authors.lastname: Tanaka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Toe
authors.forename: Hideki
authors.initials: H
authors.lastname: Nagata
authors.forename: Miki
authors.initials: M
authors.lastname: Ojima
authors.forename: Masae
authors.initials: M
authors.lastname: Kuboniwa
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kenji
authors.initials: K
authors.lastname: Osawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shizukuishi
mesh_terms: D000328:Adult; D002638:Chewing Gum; D002849:Chromatography, Gas; D004311:Double-Blind Method; D005052:Eucalyptus; D005260:Female; D005500:Follow-Up Studies; D006209:Halitosis / Q000378:metabolism / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D010936:Plant Extracts / Q000008:administration & dosage / Q000627:therapeutic use*; D013457:Sulfur Compounds / Q000032:analysis; D014059:Tongue / Q000473:pathology; D055549:Volatile Organic Compounds / Q000032:analysis; D055815:Young Adult
chemical_list: D002638:Chewing Gum; D010919:Placebos; D010936:Plant Extracts; D013457:Sulfur Compounds; D055549:Volatile Organic Compounds