title: Selecting VITA classical shades with the VITA 3D-master shade guide.
abstract: OBJECTIVE
  Although the VITA 3D-Master (3D) shade guide offers improved shade-matching performance, many dental materials are only available in VITA Classical (VC) shades. This study aimed to clarify whether it is possible to convert 3D shades determined by observers into VC shades (indirect method) without adding a clinically significant error in comparison with direct shade determination using the VC shade guide.
  
  
  METHODS
  Forty ceramic specimens were fabricated. L*a*b* values were recorded using a spectroradiometer. Sixty participants (35 dentists, 15 technicians, and 10 students) were recruited and asked to determine the shades of specimens using the VC and 3D shade guides under standardized conditions. Conversion tables were constructed by allocating the closest VC shade tab to every matched 3D shade and by use of an optimization algorithm (indirect methods). Differences between ΔE values for VC matches and for the indirect methods were evaluated using t tests.
  
  
  RESULTS
  A mean ΔE (SD) of 4.34 (2.00) for VC and 4.22 (2.21) for 3D was observed (P = .040). Compared with direct shade matching using VC, the indirect method with the optimized tables resulted in a mean ΔE of 4.32 (1.96), which was not significantly different (P = .586).
  
  
  CONCLUSIONS
  Within the limitations of this study, the conversion tables were suitable for the determination of tooth color using the 3D shade guide followed by conversion into VC shades without adding a clinically significant error.
authors.forename: Andreas
authors.initials: A
authors.lastname: Zenthöfer
authors.forename: Stefan
authors.initials: S
authors.lastname: Wiesberg
authors.forename: Achim
authors.initials: A
authors.lastname: Hildenbrandt
authors.forename: Gerhard
authors.initials: G
authors.lastname: Reinelt
authors.forename: Peter
authors.initials: P
authors.lastname: Rammelsberg
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Hassel
mesh_terms: D000328:Adult; D000465:Algorithms; D003116:Color; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003800:Dental Technicians; D003815:Dentists; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017797:Prosthesis Coloring / Q000295:instrumentation* / Q000706:statistics & numerical data; D013057:Spectrum Analysis / Q000295:instrumentation; D013335:Students, Dental; D055815:Young Adult
chemical_list: D003776:Dental Porcelain