Complete-arch accuracy of intraoral scanners

Joshua C Treesh; Peter C Liacouras; Robert M Taft; Daniel I Brooks; Sorana Raiciulescu; Daniel O Ellert; Gerald T Grant; Ling Ye

doi:10.1016/j.prosdent.2018.01.005

Complete-arch accuracy of intraoral scanners

J Prosthet Dent. 2018 Sep;120(3):382-388. doi: 10.1016/j.prosdent.2018.01.005. Epub 2018 Apr 30.

Authors

Joshua C Treesh¹, Peter C Liacouras², Robert M Taft³, Daniel I Brooks⁴, Sorana Raiciulescu⁴, Daniel O Ellert⁵, Gerald T Grant⁶, Ling Ye⁷

Affiliations

¹ Resident, Prosthodontics Department, Naval Postgraduate Dental School, Bethesda, Md.
² Director of Services, 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md; and Assistant Professor, Naval Postgraduate Dental School, Bethesda, Md.
³ Professor and Chairman, Prosthodontics Department, Naval Postgraduate Dental School, Bethesda, Md.
⁴ Statistician, Department of Research Programs, Walter Reed National Military Medical Center, Bethesda, Md.
⁵ Professor, Director of Removable Prosthodontics, Prosthodontics Department, Naval Postgraduate Dental School, Bethesda, Md.
⁶ Service Chief, 3D Medical Applications Center, Department of Radiology, Walter Reed National Military Medical Center, Bethesda, Md.
⁷ Associate Professor and Chairman, Research Department, Naval Postgraduate Dental School, Bethesda, Md. Electronic address: ling.ye.mil@mail.mil.

PMID: 29724554
DOI: 10.1016/j.prosdent.2018.01.005

Abstract

Statement of problem: Intraoral scanners have shown varied results in complete-arch applications.

Purpose: The purpose of this in vitro study was to evaluate the complete-arch accuracy of 4 intraoral scanners based on trueness and precision measurements compared with a known reference (trueness) and with each other (precision).

Material and methods: Four intraoral scanners were evaluated: CEREC Bluecam, CEREC Omnicam, TRIOS Color, and Carestream CS 3500. A complete-arch reference cast was created and printed using a 3-dimensional dental cast printer with photopolymer resin. The reference cast was digitized using a laboratory-based white light 3-dimensional scanner. The printed reference cast was scanned 10 times with each intraoral scanner. The digital standard tessellation language (STL) files from each scanner were then registered to the reference file and compared with differences in trueness and precision using a 3-dimensional modeling software. Additionally, scanning time was recorded for each scan performed. The Wilcoxon signed rank, Kruskal-Wallis, and Dunn tests were used to detect differences for trueness, precision, and scanning time (α=.05).

Results: Carestream CS 3500 had the lowest overall trueness and precision compared with Bluecam and TRIOS Color. The fourth scanner, Omnicam, had intermediate trueness and precision. All of the scanners tended to underestimate the size of the reference file, with exception of the Carestream CS 3500, which was more variable. Based on visual inspection of the color rendering of signed differences, the greatest amount of error tended to be in the posterior aspects of the arch, with local errors exceeding 100 μm for all scans. The single capture scanner Carestream CS 3500 had the overall longest scan times and was significantly slower than the continuous capture scanners TRIOS Color and Omnicam.

Conclusions: Significant differences in both trueness and precision were found among the scanners. Scan times of the continuous capture scanners were faster than the single capture scanners.

MeSH terms

Computer-Aided Design* / instrumentation
Computer-Aided Design* / standards
Dental Arch / diagnostic imaging*
Dental Prosthesis Design / methods*
Dental Prosthesis Design / standards
Humans
Printing, Three-Dimensional
Reproducibility of Results