Performance assessment of dental shade guides

Abstract 

Objectives

The goal of this study was to evaluate influence of different shade guides and respective shade matching methods on shade matching results and to analyze user satisfaction with these products and methods.

Methods

Eighty-eight pre-doctoral dental students completed the study. The color of four target shade tabs was matched using Toothguide 3D-Master (TG), Vitapan Classical (VC), and the prototype of Linearguide 3D-Master (LG). Shade matching was performed using color-corrected light source and 0/45° optical geometry. An intra-oral spectrophotometer was used for color measurements of target tabs and shade guide tabs. Results for the first 10 best matching shade guide tabs were expressed as ranks (best match – 10 points to 10th match – 1 point). Participants also performed subjective evaluation of three shade guides/tab arrangements. Descriptive statistics were calculated. T-test and Wilcoxon signed rank test were used for statistical analysis of the data (α=0.05).

Results

The best shade matching results were achieved using LG, followed by VC and TG, and the ranks were 9.1±1.2, 8.8±1.9 and 8.4±2.8. Differences in ΔE* values for the first 10 matches between TG/LG (4.5±1.8) and VC (6.2±2.2) were found to be statistically significant (p<0.001). Subjective evaluation revealed significant advantage of LG compared to TG and VC.

Conclusions

Linearguide 3D-Master enabled better shade matching results compared to Toothguide 3D-Master (p<0.05). Both 3D-Master shade guides exhibited significantly smaller ΔE* values for the first 10 matches compared to Vitapan Classical (p<0.001). Linearguide 3D-Master was superior in a subjective evaluation compared to Toothguide 3D-Master and Vitapan Classical (p<0.001).

Keywords: Color, Shade guide, Coverage error, Shade matching, Subjective evaluation