title: Tooth whitening: tooth color changes following treatment by peroxide and light.
abstract: OBJECTIVE
  This study examined the use of color measurement to determine tooth color in a study of bleaching with peroxide and light used separately and in combination. Two measurement protocols were evaluated for their ability to reveal differences between treatments and confirm tooth shade evaluations.
  
  
  METHODS
  Before and after treatment, 43 subjects were evaluated for tooth color using a shade guide and a chromameter. Two measurement procedures were used: one measured a single location on each tooth using a fabricated plastic stent, and the other measured nine locations across the buccal surface. Values from the two procedures were compared to each other, and to shade guide measurements.
  
  
  RESULTS
  Tooth color, as measured by both procedures, significantly correlated with shade evaluation. Statistically significant differences between treatment groups were found more often with data from the multiple-site procedure than from the single-site procedure. Incisal-gingival color gradation on tooth surfaces was diminished as a result of whitening treatments. Chromameter measurement data showed that tooth whitening procedures reduced tooth yellowness (b) more reproducibly than they increased whiteness (L).
  
  
  CONCLUSIONS
  When more sites per surface were measured, tooth color measurement by the chromameter more closely matched shade with less variability and greater statistical power. Chromameter-derived values can be used to estimate shade values to a reasonable level of accuracy. Decreasing yellowness, particularly at the gingival margin, was an important component of the tooth whitening effect. Following tooth whitening, teeth were more uniform in their color, and this may contribute substantially to the subjective patient recognition of whiter teeth.
authors.affiliation: Department of Clinical Research, The Forsyth Institute, Boston, MA, USA. mgoodson@forsyth.org
authors.forename: J Max
authors.initials: JM
authors.lastname: Goodson
authors.forename: Mary
authors.initials: M
authors.lastname: Tavares
authors.forename: Michael
authors.initials: M
authors.lastname: Sweeney
authors.forename: Jacyn
authors.initials: J
authors.lastname: Stultz
authors.forename: Mary
authors.initials: M
authors.lastname: Newman
authors.forename: Valerie
authors.initials: V
authors.lastname: Smith
authors.forename: Elizabeth O
authors.initials: EO
authors.lastname: Regan
authors.forename: Ralph
authors.initials: R
authors.lastname: Kent
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003116:Color; D003118:Color Perception; D003124:Colorimetry / Q000295:instrumentation; D006801:Humans; D006861:Hydrogen Peroxide / Q000627:therapeutic use*; D008027:Light; D016014:Linear Models; D008875:Middle Aged; D016877:Oxidants / Q000627:therapeutic use*; D010789:Phototherapy; D016037:Single-Blind Method; D015607:Stents; D014073:Tooth Bleaching / Q000295:instrumentation / Q000379:methods*; D014075:Tooth Discoloration / Q000628:therapy; D014978:Xenon
chemical_list: D016877:Oxidants; D014978:Xenon; D006861:Hydrogen Peroxide