Data Comparison Between Two Dental Spectrophotometers

Objectives: The objective of this study was to clinically test whether the data from two different spectrophotometers, based on spot and surface measurements, can be compared. Methods: Under standardized clinical conditions two devices (Vita Easyshade and SpectroShade-Micro) were used to record the color of three areas (cervical, middle, and incisal) per tooth for three upper maxillary anterior teeth in 102 participants. Each position was measured three times to attain an average for the CIE L*a*b* coordinates and to attain the corresponding Vita Classical shade tab integrated in the software of both devices. Vita tabs were also described as L*a*b* values using earlier published translations so that color differences (Delta E) could be calculated between them. Results: The regression analysis between the two devices showed that the independent correlation coefficients of the L*a*b* values are low. Yet when the suggested shade codes are compared with Vita colors instead of L*a*b*, 40% of the cases were equal and 51% were clinically acceptable. Significance: According to this study the two devices do not give a comparable shade selection output, and thus the exchange of L*a*b* values between the two spectrophotometers cannot be recommended.