Comparison between visual and instrumental methods for natural tooth shade matching

Tooth shade matching in daily clinical practice is still a cause of discomfort for many professionals due to the subjectivity of the process and the need for advanced training; this discomfort may lead to unsatisfactory results for the clinician and the patient. Instrumental methods were developed to simplify daily color matching procedures and to provide better esthetic outcomes. This study compared the accuracy of shade matching by both visual and instrumental methods to determine whether the instrumental method would significantly improve the process. Visual shade matching was performed by 4 dentists using a classic shade guide; instrumental shade matching was performed with a spectrophotometer by a previously calibrated examiner. Shade matching was conducted in a dental clinic under controlled illumination on the middle third of the right central incisor tooth of 30 subjects. Data were analyzed by Cohen's Kappa inter-rater agreement and by the equality of 2 proportions test (α = 0.05). Results showed statistically significant differences between the groups (76.7 ± 11.1% and 32.4% ± 7.8% for the instrumental and visual methods, respectively). Shade matching by clinicians using the instrumental method presented more agreement, and was more effective than shade matching by clinicians using the visual method.