Material-dependent trueness of intraoral scanners: A comparative analysis of three scanning technologies for different crowns – An in vitro study

AIM: The aim of this was to assess and compare the accuracy of three intraoral scanners (IOS) under clinical conditions-active triangulation (Medit i700), parallel confocal (3Shape TRIOS), and optical triangulation (Primescan) by comparing their root mean square (RMS) deviation and maximum deviations to a high-accuracy reference scan using the 3Shape E4 extraoral scanner across six different crown material substrates. SETTINGS AND DESIGN: The study was conducted in an in vitro setting, comparing different IOS technologies. MATERIALS AND METHODS: An in vitro study was performed using a three-dimensional (3D)-printed maxillary model with crowns fabricated from lithium disilicate ceramic (Emax), layered zirconia, monolithic zirconia, cobalt-chromium alloy, Polyetheretherketone (Bio-HPP), and Polyetherketoneketone (Pekkton). Each IOS performed 24 scans of the crowns following device-specific protocols. Accuracy was assessed by superimposing scans with the reference using Geomagic Control X software (Version 2020.0.1, 3D Systems, Rock Hill, SC, USA) to determine RMS and maximum deviations. STATISTICAL ANALYSIS USED: Scanning accuracy among devices and materials was evaluated using one-way analysis of variance with Tukey post hoc tests. P < 0.05 was considered to be statistically significant. RESULTS: Optical triangulation demonstrated the highest trueness for most materials, with the lowest RMS deviations for Emax (0.031 ± 0.003 mm), Bio-HPP (0.034 ± 0.002 mm), and Pekkton (0.035 ± 0.002 mm). Active triangulation performed best for the reflective cobalt-chromium alloy (0.183 ± 0.256 mm). There were significant differences seen in the accuracy of scanners and materials (P < 0.05). CONCLUSION: IOS trueness is influenced by substrate material and scanner technology. Optical triangulation excelled with translucent and low-reflective materials, whereas active triangulation showed superior performance with the reflective substrates. Material-specific scanning protocols are critical for achieving optimal clinical outcomes.