title: Color change of vital teeth exposed to bleaching performed with and without supplementary light.
abstract: OBJECTIVE
  The aim of this clinical study was to evaluate tooth color change after exposure to 25% hydrogen peroxide in-office tooth whitening system, with and without supplementary light exposure.
  
  
  METHODS
  Twenty subjects were treated with two separate 45-min exposures of bleach, with and without light using an opposing-arch design. Visual and instrumental color measurements were obtained from eighty teeth before bleaching and seven days after treatment using two different shade guides, Vitapan Classical (VC), Vita Bleachedguide 3D-Master (BG) and an intraoral spectrophotometer. Data were analyzed using ANOVA, paired t-test, and Wilcoxon signed rank tests at the 0.05 level of significance.
  
  
  RESULTS
  Instrumental method revealed significant difference in color between treatment with light (DeltaE(ab)(*)=6.0) and without light (DeltaE(ab)(*)=4.7) after seven days (p<0.05). No differences were visually detected between treatment with light and without light using the VC (p=0.56). However, a significant difference was recorded using the BG (p<0.01). Instrumental measurements of color change were in better accordance with visual findings using the BG guide (R(2)=0.60) rather than the VC (R(2)=0.20).
  
  
  CONCLUSIONS
  Within the limitations of this study, the treatment with supplementary light showed significantly greater bleaching-dependent changes in color compared to treatment without light when assessed using instrumental methods. The same was determined for the visual method with Vita Bleachedguide 3D-Master. No significant difference in color change with respect to light exposure was detected for the Vitapan Classical.
authors.affiliation: Department of Restorative Dentistry and Biomaterials, The University of Texas Dental Branch at Houston, Houston, TX 77030, USA. joe.c.ontiveros@uth.tmc.edu
authors.forename: Joe C
authors.initials: JC
authors.lastname: Ontiveros
authors.forename: Rade D
authors.initials: RD
authors.lastname: Paravina
mesh_terms: D003116:Color / Q000592:standards*; D003124:Colorimetry / Q000379:methods; D003743:Dental Enamel / Q000187:drug effects; D003804:Dentin / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008027:Light; D016014:Linear Models; D016877:Oxidants / Q000494:pharmacology; D015203:Reproducibility of Results; D013053:Spectrophotometry; D014073:Tooth Bleaching / Q000379:methods*
chemical_list: D016877:Oxidants; D006861:Hydrogen Peroxide