title: Reliability of conventional shade guides in teeth color determination.
abstract: OBJECTIVE
  Color matching in prosthodontic therapy is a very important task because it influences the esthetic value of dental restorations. Visual shade matching represents the most frequently applied method in clinical practice. Instrumental measurements provide objective and quantified data in color assessment of natural teeth and restorations. In instrumental shade analysis, the goal is to achieve the smallest deltaE value possible, indicating the most accurate shade match. The aim of this study was to evaluate the reliability of commercially available ceramic shade guides.
  
  
  METHODS
  VITA Easyshade spectrophotometer (VITA, Germany) was used for instrumental color determination. Utilizing this device, color samples of ten VITA Classical and ten VITA 3D - Master shade guides were analyzed. Each color sample from all shade guides was measured three times and the basic parameters of color quality were examined: deltaL, deltaC, deltaH, deltaE, deltaElc. Based on these parameters spectrophotometer marks the shade matching as good, fair or adjust.
  
  
  RESULTS
  After performing 1,248 measurements of ceramic color samples, frequency of evaluations adjust, fair and good were statistically significantly different between VITA Classical and VITA 3D Master shade guides (p = 0.002). There were 27.1% cases scored as adjust, 66.3% as fair and 6.7% as good. In VITA 3D - Master shade guides 30.9% cases were evaluated as adjust, 66.4% as fair and 2.7% cases as good.
  
  
  CONCLUSIONS
  Color samples from different shade guides, produced by the same manufacturer, show variability in basic color parameters, which once again proves the lack of precision and nonuniformity of the conventional method.
authors: Department of Prosthodontics, Faculty of Dentistry, University of Belgrade, Serbia. anatod2004@yahoo.com
authors: Ana
authors: A
authors: Todorović
authors: Aleksandar
authors: A
authors: Todorović
authors: Aleksandra Spadijer
authors: AS
authors: Gostović
authors: Vojkan
authors: V
authors: Lazić
authors: Biljana
authors: B
authors: Milicić
authors: Slobodan
authors: S
authors: Djurisić
mesh_terms: D002516:Ceramics / Q000627:therapeutic use; D017267:Dental Prosthesis Design / Q000379:methods / Q000592:standards; D006801:Humans; D017797:Prosthesis Coloring / Q000379:methods / Q000592:standards; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000295:instrumentation / Q000379:methods