Comparative study of visual and instrumental analyses of shade selection

Introduction: Reproducing dental color requires an accurate shade reading, that will thereafter be transferred to the laboratory technician. Aim: The purpose of this study is to assess the validity of the visual dental shade-matching, as a conventional method, compared to the spectrophotometric shade-matching. Materials and Methods: With visual analysis, 16 prosthodontists examined the middle third of the sound maxillary right central incisor of students using VITAPEN® classical and Vita Tooth- guide 3D-MASTER®. One prosthodontist examined the same teeth using a spectrophotometer. The surveys have been performed within students of Dental Medicine Faculty of Casablanca. They have been conducted by practitioners of the medical staff of the Prosthodontic Department. Results: 192 visual shade selection were performed and converted to the Lab* system color. There was no significant difference between the Vita Classic® and Vita 3D Master® shades. However, regarding occupational categories and gender, a significant difference was found. Conclusion: According to our study, the visual shade-matching has a low to moderate reproducibility compared to the spectrophotometric reading. The sensitivity and the specificity of visual shade-matching, as well as the kappa index, indicate that the conventional method cannot be considered as a reliable tool. However, the study shows that the Vita 3D Master® shade guide presents more satisfactory results regarding its intrinsic validity, compared to the Vita Classic® shade guide.