title: Determination of VITA Classical shades with the 3D-Master shade guide.
abstract: OBJECTIVE
  Because of its good matching performance the VITA 3D-Master shade guide (3D) is frequently used for determination of tooth color. Numerous composites/ceramics are, however, available in VITA Classical (VC) shades only. The objective of this study was to investigate the possibility of performing a shade match with 3D Master and converting this result via a table in a VC shade (indirect method) without this resulting in an apparent inferior shade matching in comparison with direct shade matching with the VC.
  
  
  METHODS
  Experiments were performed with an artificial, computer-generated tooth color space. Conversion tables were generated by calculating the color difference (ΔE) between a 3D shade and the closest VC shade (simple conversion table) and with the aid of optimization procedures. Statistical differences between the direct and indirect methods and between the indirect methods were assessed by use of a U-test.
  
  
  RESULTS
  Median ΔE was 2.38 for direct matching with the VC and 2.86 for indirect matching by use of a simple conversion table (p < 0.01). Optimized tables performed slightly better (median ΔE = 2.81).
  
  
  CONCLUSIONS
  Within the limitations of the study, it is usually possible to determine tooth color with the 3D and convert it, via a table, into a VC shade without adding a clinically apparent error to the direct shade match with the VC.
authors.affiliation: Department of Prosthodontics, Dental School, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. alexander.hassel@med.uni-heidelberg.de
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Hassel
authors.forename: Andreas
authors.initials: A
authors.lastname: Zenthöfer
authors.forename: Nicoleta
authors.initials: N
authors.lastname: Corcodel
authors.forename: Achim
authors.initials: A
authors.lastname: Hildenbrandt
authors.forename: Gerhard
authors.initials: G
authors.lastname: Reinelt
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiesberg
mesh_terms: D003764:Dental Materials; D021621:Imaging, Three-Dimensional
chemical_list: D003764:Dental Materials