Intrarater repeatability of shade selections with two shade guides.
BACKGROUND
Color research has shown that shade guides do not always represent the color of natural teeth. Moreover, visual evaluation has been found to be unreliable and inconsistent.


OBJECTIVE
This investigation evaluated the effects of 2 shade guides on the intrarater repeatability (reliability) of prosthodontists and general practitioners with regard to shade selection.


METHODS
Ten prosthodontists and ten general practitioners (all men, 35-45 years old) with an average practice experience of 14 years participated in this study. Examiners were tested to eliminate color blindness. Each clinician used Vita Lumin Vacuum and Vitapan 3D-Master shade guides to determine the shades of the maxillary right canines of 20 patients following a standard protocol. The identification codes of the shade tabs were masked to prevent shade memory. All teeth were polished before each shade selection, and the selection process was standardized for controlled lighting and procedures. Shade selections were randomly repeated 1 month later by the same practitioners on the same group of patients in accordance with the same shade-selection protocol. Analysis of variance and t tests for individual comparisons among means were performed (P<.05).


RESULTS
Significant interactions were found between the effects of shade guide system and specialty training on intrarater repeatability (P<.0001, analysis of variance). The intrarater repeatability of prosthodontists was significantly higher than that of general practitioners when the Vita Lumin Vacuum shade guide was used (P<.0001, t test). Use of the Vitapan 3D-Master shade guide significantly improved the intrarater repeatability of general practitioners compared with the Vita Lumin Vacuum shade guide (P<.0005). This improvement was not significant, however, among prosthodontists (P=.2861).


CONCLUSIONS
Within the limitations of this study, the prosthodontists demonstrated superior intrarater repeatability in shade selection, especially when the Vita Lumin Vacuum shade guide was used. Use of the Vitapan 3D-Master shade guide notably improved intrarater repeatability among the general practitioners.
Hammad
Ihab A
IA
Faculty of Dentistry, Alexandria University, Alexandria, Egypt. hammadfp@yahoo.com
D000328:Adult; D000704:Analysis of Variance; D003116:Color; D003118:Color Perception; D003481:Cuspid / Q000033:anatomy & histology; D017267:Dental Prosthesis Design / Q000295:instrumentation*; D004867:Equipment Design; D005792:General Practice, Dental; D006801:Humans; D008029:Lighting; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017797:Prosthesis Coloring / Q000295:instrumentation*; D011476:Prosthodontics; D015203:Reproducibility of Results; D014070:Tooth / Q000033:anatomy & histology*