title: The repeatability of digital shade measurement--a clinical study.
abstract: OBJECTIVE
  The intraoral VITA Easyshade spectrophotometer is a shade measurement system that provides for objective determination of the shade of natural teeth and of dental materials. Over a period of 2.5 years, this clinical study assessed the repeatability of VITA Easyshade measurement, using metal ceramic restorations and based on L*a*b* parameters.
  
  
  METHODS
  Shade tests of 25 metal ceramic crowns were carried out objectively in 19 patients using VITA Easyshade and subjectively by a dentist. The measurements were taken using a separate positioning device at the time of insertion, after 14 days (baseline), after 6 months, after 1.5 years and after 2.5 years.
  
  
  RESULTS
  ∆E was calculated from ∆L*, ∆a*, ∆b* data as a measure of the differences in shade. The average values during the follow-up controls were ∆E 2 = 2.2 (6 months), ∆E 3 = 2.3 (1.5 years) and ∆E 4 = 2.0 (2.5 years). Subjective shade analysis during the follow-up controls did not reveal any changes in the ceramic veneer.
  
  
  CONCLUSIONS
  The average of ∆E = 2.1 represented the difference in color. The examiner could not detect any difference in color over the evaluation period of 2.5 years.
  
  
  CONCLUSIONS
  Good results in terms of the repeatability and accuracy of VITA Easyshade measurements were reported in previous in vitro studies. Objective assessment under clinical conditions is required in order to evaluate the shade stability of tooth-colored restorative materials in the oral cavity. For this purpose, the quality and handling of VITA Easyshade must be verified from a clinical perspective.
authors: Department of Prosthodontics and Material Science, University of Leipzig, Nuernbergerstr. 57, 04103, Leipzig, Germany. constanze.olms@medizin.uni-leipzig.de
authors: Constanze
authors: C
authors: Olms
authors: Jürgen M
authors: JM
authors: Setz
mesh_terms: D003116:Color; D003124:Colorimetry / Q000295:instrumentation / Q000592:standards*; D003442:Crowns; D003793:Dental Restoration, Permanent; D003801:Dental Veneers; D005260:Female; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D013053:Spectrophotometry; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D016876:Metal Ceramic Alloys