Tooth shade selection using a colorimetric instrument compared with that using a conventional shade guide

The aim of this study was to compare the colour matching ability of instrumental colorimetry with that of a conventional visual colour matching technique.

The study was conducted in a dental clinic at the University of Otago, School of Dentistry, New Zealand.

Three dentists with normal colour vision used a Vita Classical shade guide to determine the shade of the maxillary right central incisor of 10 randomly chosen individuals. The tooth colour of the same teeth was then determined with the Shade Vision colorimeter. The examiners were not aware of one another's shade selection and colorimetric readings. The shades selected were assigned numeric Delta E values for data compilation and statistical analysis, and the degree of examiner reliability was determined using the intraclass correlation coefficient (ICC).

Analysis of the data indicated good overall interexaminer reliability for the Vita Classical shade guide (ICC = 0.62); however, the data showed poor agreement between the two shade selection techniques (ICC = 0.27).

This study found no significant difference in the accuracy of shade selection when using either a conventional visual assessment technique or a colorimetric instrument. There was, however, some discrepancy when the two shade selection techniques were compared for shade selection of the same tooth. The clinical relevance of this difference is unclear, suggesting that additional research is needed to determine the clinical advantage of using a colorimeter.