J Adv Prosthodont.  2019 Dec;11(6):331-340. 10.4047/jap.2019.11.6.331.

A new method to measure the accuracy of intraoral scanners along the complete dental arch: A pilot study

• Iturrate M
• Lizundia E
• Amezua X
• Solaberrieta E

• KMID: 2466248
• DOI: http://doi.org/10.4047/jap.2019.11.6.331

Abstract

PURPOSE
The purpose of this study is to assess the accuracy of three intraoral scanners along the complete dental arch and evaluate the feasibility of the assessment methodology for further in vivo analysis.
MATERIALS AND METHODS
A specific measurement pattern was fabricated and measured using a coordinate measuring machine for the assessment of control distances and angles. Afterwards, the pattern was placed and fixed in replica of an upper jaw for their subsequent scans (10 times) using 3 intraoral scanners, namely iTero Element1, Trios 3, and True Definition. 4 reference distances and 5 angles were measured and compared with the controls. Trueness and precision were assessed for each IOS: trueness, as the deviation of the measures from the control ones, while precision, as the dispersion of measurements in each reference parameter. These measurements were carried out using software for analyzing 3-dimensional data. Data analysis software was used for statistical and measurements analysis (α=.05).
RESULTS
Significant differences (P<.05) were found depending on the intraoral scanner used. Best trueness values were achieved with iTero Element1 (mean from 10 ± 7 µm to 91 ± 63 µm) while the worst values were obtained with Trios3 (mean from 42 ± 23 µm to 174 ± 77 µm). Trueness analysis in angle measurements, as well as precision analysis, did not show conclusive results.
CONCLUSION
iTero Element1 was more accurate than the current versions of Trios3 and True Definition. Importantly, the proposed methodology is considered reliable for analyzing accuracy in any dental arch length and valid for assessing both trueness and precision in an in vivo study.

Keyword

Intraoral scanner; Accuracy; Trueness; Digital impression; Computer-aided design and computer-aided manufacturing (CAD/CAM)

MeSH Terms

Dental Arch*
Jaw
Jupiter
Methods*
Pilot Projects*
Statistics as Topic

Figure

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  Fig. 1 Five reference cylinders in the fabricated stainlesssteel pattern.

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  Fig. 2 The model combined with the digitized pattern.

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  Fig. 3 Measured parameters in a digital impression of the upper jaw with the pattern included.

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  Fig. 4 Evolution of accuracy in terms of trueness and precision as the scanning length increases.

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  Fig. 5 Distribution of trueness and precision of each IOS in each reference distance and angle.

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