Effect of external light conditions during matching of tooth color: an intraindividual comparison.

The aim of this study was to investigate color matching under natural daylight and daylight lamp conditions. Twenty-nine preclinical students underwent a training course and then matched randomly chosen shade tabs of Vita 3D-Master Shade Guide under both natural daylight and daylight lamp conditions. Color difference (delta Eab) between presented and selected shade tabs was calculated. Statistical differences were explored by use of multivariate analyses. Mean delta Eab was 2.5 (1.0 to 4.3) with daylight lamp and 3.4 (0.9 to 7.4) with natural daylight. The difference was statistically significant (P < .001). The use of a daylight lamp helps to standardize light conditions and significantly improve the ability to match colors.