Determination of VITA Classical shades with the 3D-Master shade guide

Abstract

Objectives. Because of its good matching performance the VITA 3D-Master shade guide (3D) is frequently used for determination of tooth color. Numerous composites/ceramics are, however, available in VITA Classical (VC) shades only. The objective of this study was to investigate the possibility of performing a shade match with 3D Master and converting this result via a table in a VC shade (indirect method) without this resulting in an apparent inferior shade matching in comparison with direct shade matching with the VC. Methods. Experiments were performed with an artificial, computer-generated tooth color space. Conversion tables were generated by calculating the color difference (ΔE) between a 3D shade and the closest VC shade (simple conversion table) and with the aid of optimization procedures. Statistical differences between the direct and indirect methods and between the indirect methods were assessed by use of a U-test. Results. Median ΔE was 2.38 for direct matching with the VC and 2.86 for indirect matching by use of a simple conversion table (p < 0.01). Optimized tables performed slightly better (median ΔE = 2.81). Conclusions. Within the limitations of the study, it is usually possible to determine tooth color with the 3D and convert it, via a table, into a VC shade without adding a clinically apparent error to the direct shade match with the VC.

Key Words::

• tooth color
• shade determination
• shade guides
• conversion table
• computer simulation

Acknowledgments

We thank VITA Zahnfabrik, Bad Säckingen, Germany, for providing the CIE L*a*b* values of the shade tabs of VITA 3D Master and VITA Classical, and Ian Davies, copy editor, for English language revision.

Declaration of Interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.