Impact of Vision Defects on Tooth Shade Selection: A Comparative of Spectrophotometry and Shade Guides in a Cross-Sectional Clinical Study.

Introduction: Tooth shade selection is a fundamental factor in the success of dental restorations, and visual impairment may adversely affect this process. The aim of this cross-sectional clinical study was to determine whether visual impairment influences shade selection using two methods: spectrophotometry and shade guides. Materials and Methods: The sample consisted of 2796 maxillary and mandibular teeth, and shade selection was measured subjectively with a shade guide (VITA Classic, VITA Zahnfabrik) and objectively with a spectrophotometer (VITA Easyshade® V, VITA Zahnfabrik, Bad Säckingen, Germany). In all cases, three measurements were taken on each tooth, with a waiting time of 15 min between samples. Shade selection was compared between observers with normal vision, myopia, astigmatism, and hyperopia. Results: The results show that myopic subjects perceived the lower central incisors (2.63, p < 0.05), upper lateral incisors (2.42, p < 0.05), lower lateral incisors (2.34, p < 0.05), and lower canines (2.64, p < 0.05) more clearly. Non-astigmatic subjects perceived the lower second premolar as lighter than astigmatic subjects (-2.01, p < 0.05). Conclusions: It can be concluded that myopes see teeth more clearly, but no differences have been found in astigmatism and hyperopes.