Statement of problem
Diagnostic stone casts can be digitized by using dental optical scanners based on structured light scanning technology. Nondental structured light scanning scanners could also be used; however, the accuracy of these nondental scanners remains unclear.
The purpose of this in vitro study was to measure the scanning accuracy (trueness and precision) of 3 nondental extraoral structured light scanners.
Material and methods
A representative maxillary diagnostic cast was obtained and digitized by using an extraoral dental scanner (Advaa Lab Scan; GC Europe), and a reference or control standard tessellation language file was obtained. Three nondental extraoral scanners were evaluated: groups ND-1 (Space Spider; Artec), ND-2 (Capture Mini; Geomagic), and ND-3 (DAVID SLS3; David). Ten digital scans per group were recorded at a constant room temperature (23 °C) by an experienced geodetic engineer following the manufacturer’s recommendations. The control or reference file was used as a reference to measure the discrepancy between the digitized diagnostic cast and 3 different nondental scans by using an open-source software (CloudCompare v.2.6.1; CloudCompare) and the iterative closest point technique. The Shapiro-Wilk test revealed that the data were normally distributed. The data were analyzed by using 1-way ANOVA, followed by post hoc Bonferroni tests (α=.05).
Significant differences between the 3 experimental nondental scanners and the control or reference scan (P<.001) were found. The ND-2 group had the lowest absolute mean error (trueness) and standard deviation (precision) (39 ±139 μm), followed by the ND-3 group (125 ±113 μm) and the ND1 group (-397 ±25 μm). No statistically significant differences were found in the mean error between the ND-2 and ND-3 groups (P=.228).
Only 1 nondental extraoral scanner tested obtained trueness mean values similar to those of the reference dental scanner. In all groups, the precision mean values were higher than their trueness values, indicating low relative precision.
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Journal of Prosthetic Dentistry
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Accuracy in the digital workflow: from data acquisition to the digitally milled cast.J Prosthet Dent. 2016; 115: 749-754
- Computer-aided design and fabrication of dental restorations: current systems and future possibilities.J Am Dent Assoc. 2006; 137: 1289-1296
- Comparison of measurements made on digital and plaster models.Am J Orthod Dentofacial Orthop. 2003; 124: 101-105
- Digital dentistry: an overview of recent developments for CAD/CAM generated restorations.Br Dent J. 2008; 204: 505-511
- Comparison of the spatial landmark scatter of various 3D digitalization methods.J Orofac Orthop. 2009; 70: 247-263
- Orthodontic study cast analysis reproducibility of recordings and agreement between conventional and 3D virtual measurements.J Digit Imaging. 2010; 23: 482-492
- Two- and three-dimensional accuracy of dental impression materials: effects of storage time and moisture contamination.Biomed Mater Eng. 2010; 20: 243-249
- Comparison of the three-dimensional correctness of impression techniques: a randomized controlled trial.Quintessence Int. 2010; 41: 845-853
- Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision.J Prosthet Dent. 2013; 109: 121-128
- Comparison of accuracy and reproducibility of casts made by digital and conventional methods.J Prosthet Dent. 2015; 113: 304-309
- The fit of Procera titanium crowns. An in vitro and clinical study.Acta Odontol Scand. 1993; 51: 129-134
- A new method for the computer-aided evaluation of three-dimensional changes in gypsum materials.Dent Mater. 2003; 19: 19-24
- Accuracy of dental digitizers.Int Dent J. 2006; 56: 301-309
- Direct mechanical data acquisition of dental impressions for the manufacturing of CAD/CAM restorations.J Dent. 2007; 35: 903-908
- The accuracy of optical scanning: influence of convergence and die preparation.Oper Dent. 2011; 36: 486-491
- Reliability and validity of intraoral and extraoral scanners.Prog Orthod. 2015; 16: 38
- In vitro comparison of the accuracy (trueness and precision) of six extraoral dental scanners with different scanning technologies.J Prosthet Dent. 2016; 116: 543-550
- Precision of intraoral digital dental impressions with iTero and extraoral digitization with the iTero and a model scanner.Am J Orthod Dentofacial Orthop. 2013; 144: 471-478
- Computer aided analysis of digitized dental stone replicas by dental CAD-CAM technology.Dent Mater J. 2008; 24: 1123-1130
- Assessment of the accuracy and reliability of new 3-dimensional scanning devices.Am J Orthod Dentofacial Orthop. 2013; 144: 619-625
- Accuracy of five intraoral scanners compared to indirect digitalization.Clin Oral Investig. 2016; 21: 1445-1455
- Evaluation of the accuracy of extraoral laboratory scanners with a single-tooth abutment model: a 3D analysis.J Prosthodont Res. 2017; 61: 363-370
- An in-vitro study comparing the accuracy of full-arch casts digitized with desktop scanners.Quintessence Int. 2017; 48: 667-676
- Accuracy and efficiency of full-arch digitalization and 3D printing: a comparison between desktop model scanners, an intraoral scanner, a CBCT model scan, and stereolithographic 3D printing.Quintessence Int. 2017; 48: 41-50
- A three-dimensional evaluation of a laser scanner and a touch probe scanner.J Prosthet Dent. 2006; 95: 194-200
- Performance evaluation of optical scanner based on blue LED structured light.Procedia Eng. 2013; 63: 591-598
- ISO 5725-1. Accuracy (trueness and precision) of measurement methods and results - part 1: general principles and definitions.(Available at:)https://www.iso.org/obp/ui/#iso:std:iso:5725:-1:ed-1:v1:enDate accessed: June 1, 2018
Published online: July 11, 2020
© 2020 by the Editorial Council for The Journal of Prosthetic Dentistry.