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Investigation of firing temperature variation in ovens for ceramic-fused-to-metal dental prostheses using swept source optical coherence tomography

Todor, Raluca and Negrutiu, Meda-Lavinia and Sinescu, Cosmin and Topala, Florin Ionel and Bradu, Adrian and Duma, Virgil Florin and Rominu, Mihai and Podoleanu, Adrian Gh. (2018) Investigation of firing temperature variation in ovens for ceramic-fused-to-metal dental prostheses using swept source optical coherence tomography. In: 2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources. Proceedings of SPIE . SPIE. ISBN 978-1-5106-1674-5. E-ISBN 978-1-5106-1675-2. (doi:10.1117/12.2281892) (KAR id:66597)


One of the most common fabrication techniques for dental ceramics is sintering, a process of heating of the ceramic to ensure densification. This occurs by viscous flow when the firing temperature is reached. Acceptable restorations require the alloy and ceramic to be chemically, thermally, mechanically, and aesthetically compatible. Thermal and mechanical compatibility include a fusing temperature of ceramic that does not cause distortion of the metal substructure. Decalibration of ovens used for firing of the ceramic layers for metal ceramic dental prostheses leads to stress and cracks in the veneering material, and ultimately to the failure of the restoration. 25 metal ceramic prostheses were made for this study. They were divided in five groups, each sintered at a different temperature: a group at the temperature prescribed by the producer, two groups at lower and two groups at higher temperatures set in the ceramic oven. An established noninvasive biomedical imaging method, swept source (SS) optical coherence tomography (OCT) was employed, in order to evaluate the modifications induced when using temperatures different from those prescribed for firing the samples. A quantitative assessment of the probes is performed by en-face OCT images, taken at constant depths inside the samples. The differences in granulation, thus in reflectivity allow for extracting rules-of-thumb to evaluate fast, by using only the prostheses currently produced the current calibration of the ceramic oven. OCT imaging can allow quick identification of the oven decalibration, to avoid producing dental prostheses with defects.

Item Type: Book section
DOI/Identification number: 10.1117/12.2281892
Uncontrolled keywords: firing temperature, ceramic-fused-to-metal dental prostheses, nondestructive investigations, swept source optical coherence tomography, quantitative assessment, en-face OCT images
Subjects: R Medicine > R Medicine (General) > R857.O6 Optical instruments
R Medicine > RK Dentistry
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Funders: European Research Council (
National Institute for Health Research (
University College London (
Depositing User: Adrian Bradu
Date Deposited: 29 Mar 2018 21:27 UTC
Last Modified: 12 Jul 2022 10:41 UTC
Resource URI: (The current URI for this page, for reference purposes)

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