Almarza, R., Ghassemieh, E., Shahrbaf, S. et al. (1 more author) (2020) The effect of crown fabrication process on the fatigue life of the tooth-crown structure. Materials Science and Engineering: C, 109. ISSN 0928-4931
Abstract
Objective
To compare the fatigue strength of lithium disilicate ceramic crowns when cemented as a compound structure, as a function of the manufacturing process and the type of ceramic variation.
Method
A typodont maxillary first premolar was prepared for an all-ceramic crown in accordance with the manufacturer's guidelines for monolithic ceramic crowns (IPS e. max®; Ivoclar-Vivadent, Liechtenstein). 60 dies were duplicated in a polymer with a Young's Modulus closely matched to dentine (Alpha die, Schütz GmbH). Three different crown fabrication techniques were used (n = 20): (i) Manually applied wax spacer and pressed-crown; (ii) digitally scanned preparation, CAD-printed wax-pattern (D76PLUS, Solidscape Inc.) and pressed-crown; (iii) digitally scanned preparation and machined-crown (CEREC-inLab® v3.6 Sirona GmbH). Resin-based cement (Variolink-II®, Ivoclar-Vivadent, Liechtenstein) was employed with a standardised mechanised cementation technique to apply a controlled axial cementation pressure [Universal testing machine (Lloyd LRX®, Lloyd Materials Testing Inc)]. The samples were subjected to fatigue life testing with a cyclic impact load of 453 N for 1.25 × 106cycles at 37C⁰ and 1 Hz frequency until the point of fracture.
Result
There was a significant difference in the resistance to fatigue loading between the three groups. Weibull probability analysis and the α and β Weibull parameters indicate that the teeth restored with a ‘Manually-applied wax spacer and pressed-crown’ are best able to resist cyclic fatigue loading. They also have the most uniform interface geometry.
Conclusion
Teeth restored with IPS e. max® crowns constructed by manually applied wax spacer and pressing, have a more uniform interface and a greater structural integrity than wax CAD-printed patterns or CAD-CAM crowns.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Elsevier. This is an author produced version of a paper subsequently published in Materials Science and Engineering: C. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | Fatigue life; Tooth-crown structure; Manual press; 3D printing; Machining |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Clinical Dentistry (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 28 Jan 2020 09:25 |
Last Modified: | 09 Nov 2020 01:43 |
Status: | Published |
Publisher: | Elsevier |
Refereed: | Yes |
Identification Number: | 10.1016/j.msec.2019.110272 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:156146 |
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