Effect of Different Backgrounds and Instrumental Techniques on the Optical Properties and Shade Reproducibility of a Lithium Disilicate Glass–Ceramic

Objectives

During the shade‐matching step, digital shade‐detection tools can assist the dentist, but background factors may influence color measurement. The purpose of this study was to evaluate the influence of background on color measurements, to compare different digital shade‐detection methods, and to assess the reliability and consistency of these methods in color detection and shade matching for CAD/CAM lithium disilicate glass–ceramic.

Materials and Methods

About 15 tile‐shaped ceramic IPS e.max CAD specimens were measured using various shade‐detection devices. VITA Easyshade Advance 5.0, Trios 3 and 5, and Medit i700 intraoral scanners were used to measure VITA Classical Shade and VITA 3D Master Shade on white, gray, and black backgrounds. Repeated measurements were done for each specimen. Separate linear mixed‐effects models were constructed for each shade system to analyze the effects of instrument, background, and time.

Results

Shade measurements were significantly influenced by the instrument and background in both shade systems. For the VITA Classical Shade, instruments and backgrounds showed significant effects, with Medit exhibiting the greatest background‐related variation, while Trios 3 remained comparatively stable. White backgrounds produced higher VITA Classical Shade values than did gray or black backgrounds. For the VITA 3D Master Shade, instrument, background, and time were all significant, with VITA Easyshade Advance 5.0 showing large increases on black backgrounds and notable time‐related changes. Trios 3 and Trios 5 demonstrated greater stability across backgrounds and repeated measurements. Overall, Trios 3 provided the most consistent performance.

Conclusions

The background conditions and instrumental techniques influenced the measured shade outcomes and shade reproducibility of the ceramic. The Trios 3 intraoral scanner achieved the highest consistency in VITA Classical Shade measurements across all backgrounds. A gray background showed the highest probability of matching manufacturer VITA Classical Shade designations.

Clinical Significance: Background can affect color measurements when using digital shade‐detection tools. Selecting the correct background and tool improves ceramic shade matching.