ABSTRACT
Introduction: Color reproduction is one of the most challenging issues encountered by clinicians because of the complexity of visual properties of natural teeth.
Objectives: This study aimed to assess color differences among intended and fabricated shades of lithium disilicate restorations fabricated by CAD-CAM after using visual and instrumental shade matching systems.
Materials and Method: IPS Emax CAD blocks measuring (12.4mm width x 14.5mm length x 18 mm thickness) were cut under continuous water irrigation using diamond-impregnated slicing wheels mounted on a slow-speed saw microtome (Isomet; Buehler) to yield 16 rectangular specimens measuring (12.4 x 14.5x 1.5 mm). Then they were subjected to the crystallization cycle. Then IPS Emax glaze paste was applied with uniform thickness onto the crystallized specimen surface. Each master disk represented the color of a shade guide tab in the Vita Classic (16 shades). Shade selections for these master disks were carried out following visual and instrumental methods. Accordingly, 16 visual and 16 instrumental experimental disks were fabricated. After analysis, color differences (∆E) between the master and the fabricated ceramic discs were measured using the equation.
Results: On comparing Visual Emax CAD and instrumental Emax CAD, the mean(∆E) for visual (2.96± 1.90) was lower than the mean(∆E) for instrumental (22.22± 4.73) with a significant difference between them p < 0.001.
Conclusions: Visual shade selection using classical shade guide showed lower delta E than that of instrumental shade matching using Easyshade.
Keywords: Color duplication, lithium disilicate, E-max, Visual, Instrumental.
Running title: Color duplication using visual and instrumental methods.