The Effect of Positioning Guide Color on Shade Measurements Using a Clinical Spectrophotometer.

The purpose of this study was to investigate the influence of the color of positioning guides on the CIEL*a*b* color coordinates of ceramic, resin composite and bovine tooth surfaces measured by a clinical spectrophotometer. Positioning guides (n=10) in different colors (translucent, purple, yellow, green and, blue) were made for each surface (ceramic, resin composite and bovine tooth). The CIEL*a*b* color coordinates were measured with the positioning guides and with no positioning guide (control group).