The effect different substrates have on the trueness and precision of eight different intraoral scanners

Abstract

Objective This in vitro study compares the newest generation of intraoral scanners to their older counterparts, and tests whether material substrates affect the trueness and precision of intraoral scanners (IOS). Material and methods A custom model, used as the reference standard, was fabricated with teeth composed of different dental materials. The reference standard scan was obtained using a three‐dimensional (3D) optical scanner, the ATOS III. Experimental scans were obtained using eight different IOS, operated by experienced clinicians, using the manufacturer's recommended scanning strategy. A comprehensive metrology program, Geomagic Control X, was used to compare the reference standard scan with the experimental scans. Results For all scanners tested, except Trios3, the substrate does influence the trueness and precision of the scan. Furthermore, differences exist when comparing the same substrate across different scanners with some of the latest generation scanners clearly leaping ahead of the older generation regarding both trueness and precision. Conclusions Substrate type affects the trueness and precision of a scan. Active Triangulation scanners are more sensitive to substrate differences than their parallel confocal counterparts. Some scanners scan certain substrates better, but in general the new generation of scanners outperforms the old, across all substrates. Clinical significance The substrates being scanned play an import role in the trueness and precision of the 3D model. The new generation of scanners is remarkably accurate across all substrates and for complete‐arch scanning.

Comparing the trueness of seven intraoral scanners and a physical impression on dentate human maxilla by a novel method

“…Apart from hardware research, manufacturers make significant investments in performing software R&D to continually improve the accuracy of IOS (both trueness and precision), which can also be experienced by users after a version update [27,42]. Furthermore, many factors can influence accuracies such as scanning pattern [5,43,44] or substrate reflectance [29,30] software settings and upgraded versions [6,42]. Accuracy studies must be reevaluated from time to time due to this constant development.…”

“…Therefore, trueness values are usually assessed in vitro, on the manufactured physical samples [6,24,[44][45][46]. Recently, it has been demonstrated that the optical properties of various materials influence the accuracy of IOS, which is likely also true of mucosal tissues and other restorative and optical impression material combinations [29,30]. Therefore, this study represents a further step toward a more clinically relevant analysis by using a cadaver with representative tissues compared to artificial materials and substrates.…”

“…For modeling the effect of various optical properties of the substrate, a maxilla from a fresh human cadaver with a complete dentition was examined, during which three teeth were prepared for full tooth coverage crowns, and some teeth contained amalgam or composite fillings ( Fig. 1a) [29,30]. The dissected maxilla was kept on 4°C and wet during the test in order to conserve the condition of tissues.…”

Ceramic Materials and Technologies Applied to Digital Works in Implant-Supported Restorative Dentistry

“…Because an intraoral scanner should acquire the necessary data when capturing images of small oral structures that have many undercuts in a limited space, the data-capturing principles of the device are different from those of the extraoral scanner, which generally has a camera fixed at the top. The CEREC system (Dentsply Sirona Inc., York, PA, USA) initially used the active triangulation principle ( Figure 3A) and has recently added video sequence technology in data-capturing [14][15][16]. The iTero (Align Technology, Inc., San Jose, CA, USA) and TRIOS (3Shape, Copenhagen, Denmark) intraoral scanners are based on the principles of confocal microscopy ( Figure 3B) [15,16].…”

“…The CEREC system (Dentsply Sirona Inc., York, PA, USA) initially used the active triangulation principle ( Figure 3A) and has recently added video sequence technology in data-capturing [14][15][16]. The iTero (Align Technology, Inc., San Jose, CA, USA) and TRIOS (3Shape, Copenhagen, Denmark) intraoral scanners are based on the principles of confocal microscopy ( Figure 3B) [15,16]. The focal depth or recognition range of intraoral scanners depends on the data capture principles [17].…”