title: Use of a common shade guide to test the perception of differences in the shades and value by members of the dental team.
abstract: OBJECTIVE
  Commercial shade guides are frequently used for treatments where the shades of teeth are being reproduced or altered. Where differences between shade tabs and the natural teeth are small, difficulty is often experienced in determining the closest match. The purpose of this investigation is to discover whether the claimed colour differences between individual shades of one commonly used guide can be determined subjectively in clinical circumstances.
  
  
  METHODS
  Seventy dental team professionals made shade comparisons in an idealized colour-matching environment using shade guides as supplied by the manufacturer. Their arrangements by 'value' were recorded and unidentified shade tabs were matched with those on a complete guide.
  
  
  RESULTS
  The results showed that discrepancies existed between nominated and perceived colours, for the shade determination system tested. The shade-guide manufacturer's recommended arrangement of shade tabs ranked according to colour 'value' did not correspond to subjective perception of 'value' ordering under the conditions of the study.
  
  
  CONCLUSIONS
  There may be no practical clinical advantage in having shades which cannot be distinguished. This study indicates that colour differences between shade tabs are not clearly perceived by members of the dental team. A careful reduction of the number of tabs in the guide tested might simplify shade selection procedures and help to standardise shade-taking.
authors.affiliation: School of Clinical Dentistry, Queen's University of Belfast, Northern Ireland.
authors.forename: J L
authors.initials: JL
authors.lastname: Geary
authors.forename: M J
authors.initials: MJ
authors.lastname: Kinirons
mesh_terms: D003116:Color / Q000592:standards*; D003118:Color Perception; D005260:Female; D006801:Humans; D008297:Male; D017797:Prosthesis Coloring; D012015:Reference Standards; D014093:Tooth, Artificial