Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jan;17(1):63-69.
doi: 10.1016/j.jds.2021.07.012. Epub 2021 Jul 30.

Comparison of marginal and internal fit of 5-unit zirconia fixed dental prostheses fabricated with CAD/CAM technology using direct and indirect digital scans

Irem Gokce Uluc  1 , Mustafa Baris Guncu  1 , Guliz Aktas  1 , Ilser Turkyilmaz  2
Affiliations

Comparison of marginal and internal fit of 5-unit zirconia fixed dental prostheses fabricated with CAD/CAM technology using direct and indirect digital scans

Irem Gokce Uluc et al. J Dent Sci. 2022 Jan.

Abstract

Background/purpose: Advancements in digital dentistry and the development of intraoral scanners (IOS) have provided clinicians with an accurate and efficient alternative to analog impressions. The aim of this study was to assess the accuracy of the marginal and internal fit of 5-unit monolithic zirconia fixed dental prostheses (FDPs) fabricated with CAD/CAM technology using direct and indirect digitalization methods.

Material and methods: Three teeth in a maxillary typodont model were prepared to receive a 5-unit zirconia FDP. Six different groups were created according to the type of scanner (intraoral and extraoral) and the type of workflow. For direct workflow, the typodont was scanned with two different IOS (3Shape Trios 3 [3S-IOS] and Cerec Omnicam [C-IOS]). For indirect workflow, after conventional impressions were obtained, the impressions (IMP) were scanned with two different laboratory scanners (3S-IMP and C-IMP). After the impressions were poured, the stone (STN) casts were scanned with the same laboratory scanners (3S-STN and C-STN). Sixty 5-unit monolithic zirconia FDPs (10 in each group) were designed and milled. The marginal and internal fit was assessed.

Results: The mean marginal gap values were 78.2±9 μm in the IOS group, 82.6± 9 μm in the IMP group, and 82.6±9 μm in the STN group, indicating no statistically significant differences among groups (p > 0.05). The mean axial gap values were 77.7 ± 10 μm in IOS group, 83.61 ± 15 μm in the IMP group, and 84.5±9 μm in the STN group, indicating no statistically significant differences among groups (p > 0.05).

Conclusion: The marginal and internal fit of 5-unit monolithic zirconia FDPs fabricated with direct and indirect digital scans were similar. The smallest gap values were observed at the marginal region while the greatest gap values were detected at the occlusal region.

Keywords: Digital dentistry; Digital impression; Internal fit; Intraoral scans; Zirconia.

PubMed Disclaimer

Conflict of interest statement

The authors have no conflicts of interest relevant to this article.

Figures

Figure 1
Figure 1
Study design showing six groups according to the type of scanner used and the type digital workflow utilized.
Figure 2
Figure 2
Steps used in this study. (A) Typodont with the prepared teeth, (B) zirconia FDP seated using silicone material, and (C) silicone replica on the prepared teeth. (D) The reference and test models were accurately aligned and superimposed by using specific markers to determine the discrepancy.
Figure 3
Figure 3
Measurement regions and points for marginal and internal fit evaluations: a) marginal area between points 1 and 2, b) axial area between points 2 and 3, c) occlusal area between points 3.
See this image and copyright information in PMC

References

    1. Zhivago P., Turkyilmaz I. A comprehensive digital approach to enhance smiles using an intraoral optical scanner and advanced 3-D sculpting software. J Dent Sci. 2021;16:784–785. - PMC - PubMed
    1. Turkyilmaz I., Unsal G.S. Full-mouth rehabilitation of an elderly patient with Sjogren's syndrome by using implant-supported fixed dental prostheses including CAD/CAM frameworks. J Dent Sci. 2019;14:428–429. - PMC - PubMed
    1. Turkyilmaz I., Samantha L., Tarrida L.G., Varvara G. Guest commentary: the battle of file formats from intraoral optical scanners. Int J Prosthodont (IJP) 2020;33:369–371. - PubMed
    1. Guth J.F., Keul C., Stimmelmayr M., Beuer F., Edelhoff D. Accuracy of digital models obtained by direct and indirect data capturing. Clin Oral Invest. 2013;17:1201–1208. - PubMed
    1. Su T.S., Sun J. Intraoral digital impression technique: a review. J Prosthodont. 2015;24:313–321. - PubMed