Comparison between intraoral scanner and spectrophotometer shade matching: A systematic review and meta-analysis

This systematic review (SR) and meta-analysis (MA) aimed to compare the accuracy of shade selection of intraoral scanners (IOSs) to spectrophotometers (SPs) as reference standards. Studies comparing the trueness (percentage of the correct match and ΔE) and precision (repeatability and percentage of the same match) of IOS and SP determination were included in this study. An electronic search of five databases was conducted in May 2022. A total of 112 studies were identified from the databases, among which 22 articles were eligible for inclusion. After study selection and data extraction, MA was performed to define the accuracy of IOS in subgroups using four outcomes: the percentage of the correct match in Vita Classical shade guide system (VC), percentage of the correct match in 3D master shade guide system (3D), percentage of the correct match in VC and percentage of the same match in 3D. Cochrane guidelines, Joanna Briggs Institute (JBI) Checklist and GARDE were used for the risk of bias and certainty assessments. From the 22 articles, 10 articles were included for the MA. The percentage of the correct shade matching with IOS was 20% [confidence interval (CI): 0.05-0.52] with VC and 23% (CI: 0.06-0.59) with 3D. The repeatability of shade matching by IOSs was between 81% (CI: 0.64-0.91) with VC and 81% (CI: 0.65-0.91) with 3D master shade guide systems. The trueness of shade matching with IOS is low compared to that with SPs, although the precision is considered high. Shade determination using IOS alone is not recommended.