Repeatability of a dental shade-matching instrument when compared to traditional visual methods of shade evaluation

Electronic shade-matching instruments are available for clinical use; however, their accuracy has not been established. This study evaluated a new electronic method of clinical shade matching compared to the standard visual method. The Vita Easyshade system, an electronic method of shade matching, was used on 40 subjects to measure the central region of each patient's maxillary left central incisor (tooth No. 9). Two visual evaluators with predetermined visual shade matching abilities selected a shade from the same area of tooth No. 9 for all subjects. Student's t-test, using a 95% score confidence interval (CI), was used to compare the two methods. The Vita Easyshade system was accurate 85% of the time in this in vivo study; however, the instrument was predictably accurate only 68-91% of the time at the 95% CI.