Visual and Spectrophotometric Shade Analysis of Human Teeth

Abstract

Due to interhuman differences in the perception of color, visual shade assessment of human teeth is lacking standardization that may be improved by the use of a spectrophotometer. In this study, we tested the hypothesis that spectrophotometric assessment of tooth color is comparable with human visual determination. On 30 patients, three operators with unreported visual color deficiency independently selected the best match to the middle third of unrestored maxillary central incisors, using a Vita Classical Shade Guide. The same teeth were measured by means of a reflectance spectrophotometer. In the human group, all 3 visual shade selections matched in only 26.6%. In the spectrophotometric group, all 3 shade selections matched in 83.3%. In 93.3%, Delta E values of visually assessed tooth shades were higher than spectrophotometrically assessed Delta E values (p < 0.0001). The results suggest that spectrophotometric shade analysis is more accurate and more reproducible compared with human shade assessment.