Evaluating percent correct shade identification: A practical approach to intraoral scanner and shade device performance

Abstract

Objectives The study aimed to assess the percent correct shade identification of four intraoral scanners (IOS) and a spectrophotometer, focusing on how reliably each device selects the correct tooth shade compared to a visual observer’s selection. The research question addresses how much clinicians can trust the device-selected shade without visual verification. Materials and Methods Sixteen participants with natural, unrestored teeth were included. The teeth evaluated were tooth 21 (left maxillary central incisor), tooth 23 (left maxillary canine), and tooth 26 (first left maxillary molar). Tooth color was measured using four IOS devices and the Vita Easyshade V in three regions: incisal, middle, and cervical. The nearest 3D Master shade selected by each device was compared to the visual observer’s selection. The percent exact match, acceptable match (> 1.2, ≤ 2.7 ∆Eab), and mismatch type A (< 2.7, ≤ 5.4 ∆Eab) were calculated. Statistical analysis was performed using a chi-square test with a 95% confidence level. Results The overall clinical pass rate was highest for Carestream (78.2%), followed by Easyshade (63.5%), Primescan (51.2%), Trios (39.5%), and Medit (31.3%). Carestream also recorded the highest rate of mismatch type A (47.7%). Significant differences between devices were observed for all categories (p < 0.05). Conclusions Carestream demonstrated the highest overall clinical pass rate, while Medit exhibited the lowest. The study highlights the variability between devices in shade matching performance. Clinical Relevance This study highlights the importance of considering device performance when relying on IOS or spectrophotometers for shade selection without visual assessment, as the reliability can vary significantly across devices.