title: Influence of light source, polarization, education, and training on shade matching quality.
abstract: BACKGROUND
  Many factors influence the quality of shade selection, and isolating how significantly each of these factors influences results is difficult.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to compare results of shade matching using handheld lights with or without a polarizing filter with results obtained using a professional viewing booth and to analyze the influence of education and training on shade selection outcome.
  
  
  METHODS
  A total of 96 third-year dental students (evaluators) were randomly separated into 4 groups. Each group was assigned 1 of 2 handheld shade-matching devices (lights) with or without a polarizing filter. Each group performed a shade matching exercise using the handheld light or a professional viewing booth. The exercise consisted of matching shade tabs placed in a typodont to a commercial shade guide. Each group repeated this procedure 4 times over a 9-week period. A lecture on shade matching was presented at the fifth week of the study, between "before" and "after" shade matching procedures.
  
  
  RESULTS
  Shade matching scores with handheld lights (7.8) were higher than scores of shade matching with the viewing booth (7.2). The mean scores for before (7.2) and after (7.8) shade matching (with education and training in between) were significantly different. The combined effect of light and education and training improved the shade matching score by 1.2, from 6.8 in the before sessions using the viewing booth to 8.0 in the after sessions using handheld lights. A 21% increase in the number of evaluators who selected 1 of 4 best matches was recorded, 10% for handheld lights versus viewing booth after education and training versus before sessions and 11% between after sessions using handheld lights versus before sessions using viewing booth.
  
  
  CONCLUSIONS
  Within the limits of the study, the shade matching scores with handheld lights were significantly better than the results obtained using a viewing booth (P<.01). Using a handheld light with or without a polarizing filter did not influence shade matching results. Mean shade matching scores were significantly better after education and training (P<.01). Light combined with education and training resulted in the greatest increase in shade matching quality.
authors: Resident, Department of Restorative Dentistry and Prosthodontics, University of Texas School of Dentistry at Houston, Houston, Texas.
authors: Jacqueline A
authors: JA
authors: Clary
authors: Professor, Department of Restorative Dentistry and Prosthodontics, University of Texas School of Dentistry at Houston, Houston, Texas.
authors: Joe C
authors: JC
authors: Ontiveros
authors: Senior Statistician, Center for Nursing Research, University of Texas School of Nursing at Houston, Houston, Texas.
authors: Stanley G
authors: SG
authors: Cron
authors: Professor, Department of Restorative Dentistry and Prosthodontics, and Director, Houston Center for Biomaterials and Biomimetics, University of Texas School of Dentistry at Houston, Houston, Texas. Electronic address: rade.paravina@uth.tmc.edu.
authors: Rade D
authors: RD
authors: Paravina
mesh_terms: D002983:Clinical Competence; D017267:Dental Prosthesis Design / Q000379:methods / Q000592:standards; D004497:Education, Dental; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D017797:Prosthesis Coloring / Q000379:methods / Q000592:standards; D013335:Students, Dental