title: Color comparison of two shade guides.
abstract: OBJECTIVE
  The aim of this study was to analyze color parameters and color compatibility of two randomly chosen Vita shade guides, as well as to propose possible clinical guidelines.
  
  
  METHODS
  Data were recorded using a colorimeter set to standard illuminant source C and the CIE L*a*b* system. A custom adapter system, which allowed a measuring area at the middle third of the tabs, was produced. Each of 42 tabs was recorded one time each on three different days. Color distribution was examined in diagrams whose coordinates were L*a*b* and L*C*H degree color coordinate pairs. Color coordinate ranges and coverage error were examined using the corresponding equations and statistical methods.
  
  
  RESULTS
  The method repeatability was approximately delta E* = 0.1. Color difference ranges of Vitapan Classical and Vitapan 3D Master were 14.3 and 19.2, respectively. Color coordinate ranges of Vitapan Classical were as follows: delta L* = 12.8; delta a* = 1.7; delta b* = 9.0; delta C* = 9.0; and delta H degree = 7.4. Corresponding values for Vitapan 3D Master were delta L* = 15.3; delta a* = 3.4; delta b* = 16.3; delta C* = 16.6; and delta H degree = 10.5. Coverage error of Vitapan 3D Master to Vitapan Classical was 1.4 +/- 0.6, while vice versa it was 2.0 +/- 1.5.
  
  
  CONCLUSIONS
  Compared to Vitapan Classical, chromaticity ranges of Vitapan 3D Master were extended in the desired directions: hue was extended toward yellow-red, and saturation was extended toward more saturated tabs. Compared to Vitapan Classical, Vitapan 3D Master tabs were more uniformly spaced. The examined shade guides were found to be color compatible.
authors.affiliation: Department of Restorative Dentistry and Biomaterials, University of Texas Health Science Center at Houston, Dental Branch, 6516 Anderson Boulevard, Houston, Texas 77030-3402, USA. rparavina@uth.tmc.edu
authors.forename: Rade D
authors.initials: RD
authors.lastname: Paravina
authors.forename: John M
authors.initials: JM
authors.lastname: Powers
authors.forename: Rose-Marie
authors.initials: RM
authors.lastname: Fay
mesh_terms: D003116:Color / Q000592:standards*; D003124:Colorimetry; D017267:Dental Prosthesis Design; D017797:Prosthesis Coloring; D015203:Reproducibility of Results