title: Whitening effect by stain inhibition from a chewing gum with sodium hexametaphosphate in a controlled twelve-week single-blind trial.
abstract: OBJECTIVE
  A twelve-week clinical study was conducted to assess the effect of a chewing gum containing sodium hexametaphosphate (4%) on the inhibition of stain formation.
  
  
  METHODS
  Fifty-four subjects were entered and completed all aspects of the study. Twenty-seven of the subjects were smokers, and the other half did not smoke. Subjects were randomly assigned to the test gum or no-gum group. Each participant received a full oral prophylaxis at the beginning of each period of observation. Those chewing the test gum agreed to chew four times a day, for five minutes each time, over twelve weeks. Those assigned to the no-gum group agreed not to chew any gum. After twelve weeks, participants were scored for stain deposits (Lobene Index), received a second oral prophylaxis, and joined the alternate group in this cross-over format. At the end of the twenty-fourth week, all subjects were again scored for stain deposits and the study was completed. In order to enhance stain formation during the entire 24-week study period, all participants received a supply of a chlorhexidine (0.12%) dentifrice without anionic agents to use three times a day. Stain levels were scored by the same examiner for all measurements and recorded on computer. The examiner was blinded to all treatment assignments.
  
  
  RESULTS
  There were no reported problems associated with the chewing gum. The Lobene Index mean score for stain extent was 0.54 +/- 0.36) in the test-gum group and 0.81 +/- 0.47) for the no-gum group. The difference between the mean scores was highly significant with paired sample t-test (p < 0.001). Mean stain intensity was 0.57 +/- 0.38) in the test group and 0.95 (+/- 0.72) in the control group, with a statistically significant difference at p < 0.01.
  
  
  CONCLUSIONS
  The results indicated that chewing gum containing sodium hexametaphosphate reduced induced stain formation by 33% compared to a no-gum treatment.
authors.affiliation: University of Siena, Dental School, Siena, Italy. piercateadsl@libero.it
authors.forename: Pier Francesco
authors.initials: PF
authors.lastname: Porciani
authors.forename: Simone
authors.initials: S
authors.lastname: Grandini
authors.forename: Caterina
authors.initials: C
authors.lastname: Perra
authors.forename: Romano
authors.initials: R
authors.lastname: Grandini
mesh_terms: D000293:Adolescent; D000328:Adult; D002638:Chewing Gum; D018592:Cross-Over Studies; D003802:Dentifrices / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000008:administration & dosage / Q000627:therapeutic use*; D016037:Single-Blind Method; D012907:Smoking; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000517:prevention & control*
chemical_list: D002638:Chewing Gum; D003802:Dentifrices; D010710:Phosphates; C009285:sodium polymetaphosphate