Clinical evaluation of the repeatability of three colour measuring devices

Objective: The objective of this clinical study was to undertake a clinical evaluation of the repeatability of three colour measuring devices. Methods: Under standardized clinical conditions a single operator using three colour measuring devices (Vita Easyshade, X-Rite ShadeVision and Spectroshade Micro) recorded three shade measurements (cervical, body, and incisal) for each of the upper maxillary anterior teeth in twenty participants. This sequence of measurements was repeated for each of the shade machines. The output recorded from each sequence included Vita shades and CIE Lab co-ordinates. Ethical approval was obtained from the joint University College London and University College London Hospitals. Results: Spectroshade Micro had good agreement Cohen Kappa score (.80) for repeatability of vita shades and also had 82.7% proportion of complete agreement for Vita shades. The proportion of complete agreement for Vita shades for the Easyshade and X-Rite ShadeVision machine were 50% and 59% respectively. For CIE Lab and CIE Lch co-ordinates the Spectroshade Micro provided the narrowest range of ‘Bland and Altman' agreement limits for all the co-ordinates recorded. Conclusion: The Spectroshade Micro machine provided the most repeatable measurements. Narrower limits of agreement indicate greater consistency compared to Easyshade and the X-Rite ShadeVision.