Lighting conditions used during visual shade matching in private dental offices

Statement of problem. To our knowledge, no data are available on the actual lighting that is used for visual shade matching in private dental offices. Purpose. The purpose of this study was to determine the shade matching practices and interest in continuing education in dental practices and to determine the quantity and quality of the ambient lighting used during visual shade matching in a sample cohort of dentists in private practices. Material and methods. Thirty-two private practices were enrolled, and each completed a 1-page survey on the clinic's shade matching practices. A spectrophotometer was used to measure the ambient lighting in each practice, collecting data on color temperature (Kelvin), color rendering index (CRI), and light intensity (foot candles/fc). A 2-sided nonparametric sign test was used to compare the true median color temperature with the standard (5500 degrees K). A 1-sided t test was used to compare the CRI with the standard (CRI >90) (alpha=.05 for all statistical analyses). Results. All dental practitioners surveyed used mainly visual shade matching in their practices. Of those, 87.5% showed interest in attending continuing education on this topic, with 56.3% preferring a clinical demonstration course. The mean color temperature was 4152.9 degrees K and was significantly different from the standard 5500 degrees K (P<.001). The 1-sided t test indicated that the mean CRI was less than 90 (P=1). The 95% confidence interval for the intensity was 80.7 to 111.6 fc. Conclusions. The ambient light in the majority of the 32 dental private practices measured was not ideal for visual shade matching.