title: Development of a customized whiteness index for dentistry based on CIELAB color space.
abstract: OBJECTIVE
  To develop a customized CIELAB-based whiteness index for dentistry that accurately correlates to perception of tooth whiteness.
  
  
  METHODS
  Four psychophysical experiments (PE1-4) were conducted by three panels of observers (OP1-3) under diffuse/0° observation/measuring conditions and under typical clinical viewing conditions. Nine whiteness indices (WI, Z%, WIC, WIO, W31, W64, W, WLAB, W*), two yellowness indices (YID1925, YIE313) and tint of white in the CIELAB color system (T) were compared with regard to their ability to measure the perceived whiteness of human teeth. Determination coefficient (R(2)) and '% wrong decision' (%WD) method were used as direct measures of the quality of the indices for whiteness perception in dentistry.
  
  
  RESULTS
  CIELAB-based whiteness index (WID=0.511L* -2.324a* -1.100b*) was developed through optimization from the data obtained in PE1. The proposed WID performed better than all the CIELAB and CIE1931 XYZ-based indices under laboratory and clinical conditions (only WIO was comparable to WID in PE2 and PE4).
  
  
  CONCLUSIONS
  The validation experiments under laboratory and typical clinical conditions revealed that the proposed index WID outperformed previous indices, being the only CIELAB-based index developed for evaluation of whiteness in dentistry.
authors.affiliation: Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain; Houston Center for Biomaterials and Biomimetics, Department of Restorative Dentistry and Prosthodontics, University of Texas, School of Dentistry, 7500 Cambridge St., Houston, TX 77054, USA. Electronic address: mmperez@ugr.es.
authors.forename: María del Mar
authors.initials: Mdel M
authors.lastname: Pérez
authors.affiliation: Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain; Houston Center for Biomaterials and Biomimetics, Department of Restorative Dentistry and Prosthodontics, University of Texas, School of Dentistry, 7500 Cambridge St., Houston, TX 77054, USA.
authors.forename: Razvan
authors.initials: R
authors.lastname: Ghinea
authors.affiliation: Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Rivas
authors.affiliation: Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Yebra
authors.affiliation: Department of Optics, Faculty of Science, University of Granada, Campus Fuente Nueva, Edificio Mecenas, s/n 18071, Granada, Spain.
authors.forename: Ana María
authors.initials: AM
authors.lastname: Ionescu
authors.affiliation: Houston Center for Biomaterials and Biomimetics, Department of Restorative Dentistry and Prosthodontics, University of Texas, School of Dentistry, 7500 Cambridge St., Houston, TX 77054, USA; Department of Restorative Dentistry and Prosthodontics, The University of Texas Dental Branch at Houston, 7500 Cambridge Dr., Ste. 5437, Houston, TX 77054, USA.
authors.forename: Rade D
authors.initials: RD
authors.lastname: Paravina
authors.affiliation: Department of Computer Architecture and Computer Technology, E.T.S.I.I.T. University of Granada, s/n 18071, Granada, Spain.
authors.forename: Luis Javier
authors.initials: LJ
authors.lastname: Herrera
mesh_terms: D003116:Color / Q000592:standards*; D003118:Color Perception; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design / Q000592:standards*; D004955:Esthetics, Dental; D006801:Humans; D015588:Observer Variation; D017797:Prosthesis Coloring / Q000592:standards*; D011601:Psychophysics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014075:Tooth Discoloration / Q000145:classification*
chemical_list: D003764:Dental Materials
keywords: CIELAB color space; Dental materials whiteness; Tooth whiteness; Visual assessments; Whiteness index