Differences between the human eye and the spectrophotometer in the shade matching of tooth colour

ObjectivesThe aim of this work was to assess the agreement between instrumental and visual colour matching.MethodsShade selection with the 3DMaster Toothguide (Vita-Zahnfabrik) was performed for 1361 maxillary central incisors and compared with the shade obtained with the EasyShade Compact (Vita-Zahnfabrik) spectrophotometer.ResultsWe observed a greater correlation between the objective method and the subjective one in the colour dimension of lightness (Kappa 0.6587), followed by hue (Kappa 0.4337) and finally chroma (Kappa 0.3578).ConclusionThe colour dimension in which the greatest agreement is seen between the operator and the spectrophotometer is value or lightness.Clinical significanceThis study reveals differences between the measurement of colour via spectrophotometry and the visual shade selection method. According to our results, there is better agreement in the value or lightness colour dimension, which is the most important one in the choice of tooth colour.