Document Type
Article
Publication Date
Spring 3-24-2023
Abstract
Purpose: The aim was to assess the effect of span lengths and total occlusal
convergence (TOC) on the accuracy of intraoral scanners .
Materials and methods: Two typodont acrylic teeth models were prepared to receive
fixed dental prostheses with three different span lengths. Span 1: between maxillary
canines; span 2: between maxillary second premolars; and span 3: between maxillary
In recent years, the employment of digital techniques in
1–4
(CAD–CAM). Obtaining a digital scan using an intrao-
ral scanner (IOS) is the first step of this digital workflow.
This technique, when compared to traditional impression
techniques, has shown exceptional accuracy for short-span
Depending on the optical method employed to capture the
data, IOS can be divided into different categories. Active
triangulation, confocal microscopy, optical coherence tomog-
raphy, and active wavefront sampling are the most often
8
Examples encompass computer-aided design and computer-aided manufacturing
5
dentistry has evolved remarkably.
second molars. In the first model, prepared teeth had a TOC of 12◦, whereas, in the ◦
second model, teeth had a TOC of 20 . Each model was scanned 10 times using 4 different intraoral scanners (Omnicam, Primescan, Trios 4, and Medit i500). The STL files from the scans were compared to the reference models (trueness) and within each test group (precision) using a 3D comparison software. Data were then statistically analyzed.
Results: Regarding trueness, no significant differences were found among Primescan (32.58 ± 13.08), Trios 4 (32.33 ± 12.19), and Medit i500 (32.26 ± 9.57). However, all showed significantly better trueness than Omnicam (35.70 ± 8.35) (p < 0.001). The highest values were found in scans between the second molars (47.42 ± 3.94), fol- lowed by scans between second premolars (28.42 ± 3.78), and the highest trueness was found in scans between the canines (23.80 ± 3.85). For TOC, 12◦ had a significantly higher value than 20◦ (p < 0.001). Regarding precision, the highest values were found with Omnicam (29.84 ± 3.89), followed by Medit i500 (28.04 ± 2.94), then Trios 4 (25.64 ± 3.11), and Primescan (24.69 ± 5.25). The highest values and least precision were found in scans between the second molars (28.97 ± 5.27) and scans between second premolars (27.59 ± 3.97), whereas the highest precision was found in scans between the canines (24.60 ± 2.04). For TOC, 12◦ had significantly higher values than 20◦ (p < 0.001).
Conclusions: Intraoral scans are directly affected by scanner type, TOC, and scan spans. All tested scanners showed clinically acceptable results even for long-span restorations.
Recommended Citation
Elsergany, Omar, "Effect of different span lengths with different total occlusal convergences on the accuracy of intraoral scanners" (2023). Dentistry. 417.
https://buescholar.bue.edu.eg/dentistry/417
