title: The repeatability of an intraoral dental colorimeter.
abstract: BACKGROUND
  Characterizing and reproducing color remain one of the most challenging aspects of dentistry. A relatively new intraoral colorimeter measures the color of natural teeth and metal-ceramic restorations and prints out a color recipe for the Vintage Halo Porcelain System. The reliability of the colorimeter is unknown.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the reliability of a contact dental colorimeter and to correlate the shade registered by the colorimeter with the shade selected by experienced clinicians.
  
  
  METHODS
  In part I of the study, 2 examiners (A and B) took 2 colorimeter measurements from the maxillary right central incisors of 11 subjects. The examiners were blinded to their own data and those of other investigators. The readings were repeated 3 weeks later with the same protocol. The Cronbach alpha reliability coefficient was used to analyze the collected data. In part II of the study, 2 experienced clinicians (examiners D and E) selected a shade from the classic Vita Lumin Vacuum shade guide for the maxillary right central incisors of the same 11 subjects. The clinicians were blinded to each other's selections and the colorimeter readings. It should be noted that the manufacturer of the colorimeter uses the terms shade, value, and hue to represent chroma, value, and hue, respectively, as defined in the Glossary of Prosthodontic Terms (J Prosthet Dent 1999;81:39-110).
  
  
  RESULTS
  The reliability analysis results for each of the combined trials for shade, value, and hue were all >.94. The interexaminer reliability alpha values were >.9 for shade and value and.64 to.74 for hue. The interexaminer alpha represented the value range of each of 4 measurements. The intraexaminer reliability alpha values for shade, value, and hue were.99,.95, and.96 for examiner A and.99,.93, and.97 for examiner B, respectively. In part II of the study, the colorimeter agreed with itself 82% of the time, whereas clinicians agreed with each other on the selected shade 73% of the time. Selections made by the colorimeter and the clinicians matched 55% to 64% of the time.
  
  
  CONCLUSIONS
  Within the limitations of this study, the colorimeter reliably measured the color of natural teeth.
authors.affiliation: College of Dentistry, New York University, New York, N.Y. 10010, USA. fft1@nyu.edu
authors.forename: Francis F
authors.initials: FF
authors.lastname: Tung
authors.forename: Gary R
authors.initials: GR
authors.lastname: Goldstein
authors.forename: Sungkoo
authors.initials: S
authors.lastname: Jang
authors.forename: Eugene
authors.initials: E
authors.lastname: Hittelman
mesh_terms: D002516:Ceramics / Q000737:chemistry; D003116:Color; D003118:Color Perception; D003124:Colorimetry / Q000295:instrumentation* / Q000706:statistics & numerical data; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design / Q000295:instrumentation; D006801:Humans; D016876:Metal Ceramic Alloys / Q000737:chemistry; D015588:Observer Variation; D015203:Reproducibility of Results; D016037:Single-Blind Method; D014070:Tooth / Q000033:anatomy & histology*
chemical_list: D003764:Dental Materials; D016876:Metal Ceramic Alloys