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Temperature variations in sintering ovens for metal ceramic dental prostheses: Non-destructive assessment using OCT

Sinescu, C., Bradu, Adrian, Duma, V.F., Topala, F.I., Negrutiu, M.L., Podoleanu, Adrian G.H. (2018) Temperature variations in sintering ovens for metal ceramic dental prostheses: Non-destructive assessment using OCT. In: Proc. SPIE 10473, Lasers in Dentistry XXIV, 104730C. . (doi:10.1117/12.2289162) (KAR id:66796)

Abstract

We present a recent investigation regarding the use of optical coherence tomography (OCT) in the monitoring of the calibration loss of sintering ovens for the manufacturing of metal ceramic dental prostheses. Differences in the temperatures of such ovens with regard to their specifications lead to stress and even cracks in the prostheses material, therefore to the failure of the dental treatment. Evaluation methods of the ovens calibration consist nowadays of firing supplemental samples; this is subjective, expensive, and time consuming. Using an in-house developed swept source (SS) OCT system, we have demonstrated that a quantitative assessment of the internal structure of the prostheses, therefore of the temperature settings of the ovens can be made. Using en-face OCT images acquired at similar depths inside the samples, the differences in reflectivity allow for the evaluation of the differences in granulation (i.e., in number and size of ceramic grains) of the prostheses material. Fifty samples, divided in five groups, each sintered at different temperatures (lower, higher, or equal to the prescribed one) have been analyzed. The consequences of the temperature variations with regard to the one prescribed were determined. Rules-of-thumb were extracted to monitor objectively, using only OCT images of currently manufactured samples, the settings of the oven. The method proposed allows for avoiding producing prostheses with defects. While such rules-of-thumb achieve a qualitative assessment, an insight in our on-going work on the quantitative assessment of such losses of calibration on dental ovens using OCT is also made.

Item Type: Conference or workshop item (Proceeding)
DOI/Identification number: 10.1117/12.2289162
Uncontrolled keywords: Biomedical imaging, Dental Medicine, Optical Coherence Tomography (OCT), metal ceramic dental prostheses, sintering ovens, non-destructive testing (NDT), temperature monitoring, effects of sintering temperatures.
Subjects: Q Science > QC Physics > QC355 Optics
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Adrian Bradu
Date Deposited: 19 Apr 2018 22:11 UTC
Last Modified: 09 Dec 2022 02:49 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/66796 (The current URI for this page, for reference purposes)

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