Effects of different light sources on tooth shade selection

Differences in lighting conditions can make matching the shade of a single porcelain tooth to the natural adjacent teeth very challenging.

The purpose of the study was to examine visual shade selection under 3 different light sources - natural daylight, a dental operating light and a color-corrected light.

The visual assessment was based on a comparison between a shade guide and the target tooth. One observer with normal color vision was asked to visually match the color of the maxillary central right incisor and the maxillary right canine in a group of 100 subjects, aged 22-40 years. Two shade guides were used - VITA Vitapan Classical® and VITA 3D Master® - in natural daylight as well as under an operating light and a handheld light (Demetron Shade Light®). The VITA Easyshade® spectrophotometer was used to evaluate the results of the visual shade selection method.

Significant differences were found between the effects of using the shade guide systems (p < 0.05) and light sources (p < 0.05). Overall, the use of the Vitapan Classical shade guide significantly improved the correlation between visual matching and the spectrophotometer readings.

Within the limitations of this study, the Vitapan Classical shade guide demonstrated superior agreement in shade selection as compared to the 3D Master shade guide. The Demetron Shade Light was proven to be a useful device for the color matching of artificial teeth in prosthodontic treatment. Visual tooth color matching is a subjective method and it produces the best results under a color-matching light.