Comparison of the Clinical Evaluation of Digital Tooth Shade Determination Using an Intraoral Scanner with Proven Subjective and Objective Methods

Background/Objectives: Despite the increasing use of chromatic intraoral scanners, color determination is often performed visually, offering poor reliability and validity. In this study, we aimed to compare the reliability and validity of the tooth shade determination tool of an intraoral scanner (Trios3 Color) with that of two dental spectrophotometers (VITA Easyshade Advance 4.0 and SpectroShade Micro) and with visual determination using the VITA 3D-Master shade guide. Methods: In vivo tooth shade determination was performed on 33 participants using positioning splints for the right central incisor. Repeated measurements assessed the reliability in determining the percentage agreement with VITA 3D-Master shades. VITA Easyshade measurements were used as reference values for validity. The metric value Delta E (ΔE) in the International Commission on Illumination L*a*b* color space was compared to the reference, with ΔE greater than 1 indicating visible differences and a maximum value of ΔE 6.8 being clinically acceptable. Results: The reliabilities of VITA Easyshade, the intraoral scanner, and SpectroShade Micro were 75.8%, 87.9%, and 89.9%, respectively. The visual method had an agreement rate of 20.6%. Validity values, compared with the reference value, were ΔE 3.8 (clinically acceptable), 8.3, and 7.4 (the latter two both being clinically unacceptable) for the intraoral scanner, area-measuring device, and visual method, respectively. Conclusions: The intraoral scanner is a reliable and valid tool for tooth shade determination and is superior to the visual method in both aspects.