Shade determination based on digital photographs and different sources of illumination. An in-vivo, pilot study

The aim of the study was to compare shade estimation in maxillary anterior teeth under different ambient light sources, whilst using digital photography.

In this study different ambient light conditions were considered for shade determination. 96 readings were obtained from six maxillary anterior teeth were selected for this study, and shade was determined at the middle 1/3rd of the tooth using a digital spectrophotometer and the L∗a∗b∗values obtained, which was the control. Photographs were taken as per the different light sources. The photographs were then subjected to a Classic Color Meter software to derive the L∗a∗b∗ values. The L∗a∗b∗ values obtained were statistically analysed and results obtained.

The results depicted that cool white light as compared to the digital spectrophotometer showed better results with statistically insignificant difference in the L∗ category (p = 0.598) & b category (p = 0.143). Warm white light was also comparable only in the L∗ category (p = 0.903). Natural sunlight showed similar results when compared in the L∗ category (p = 0.939), but varied significantly in a∗ and b∗ categories. While LED Ceiling light showed the most significantly different results under all categories of L∗, a∗ and, b∗.

It was concluded that digital photography method of shade estimation can be a reliable method of shade estimation under cool white light illuminance. Warm white light and natural sunlight are dependable measures for value matching, whereas LED ceiling lights yielded inaccurate shades through the digital photography method of shade estimation in all axes of the CIELAB space.