The Effect of Firing Cycles on the Fit of Cobalt-Chromium Multiunit Prostheses Fabricated by Additive Manufacturing.

Autor: Daou EE; Department of Prosthodontics, Faculty of Dental Medicine, Lebanese University, Beirut, Lebanon.; Al-Ayen University, Nile Street, Nasiriyah., Baba NZ; Advanced Specialty Education Program in Implant Dentistry, Loma Linda University, School of Dentistry, California, USA.
Jazyk: angličtina
Zdroj: Journal of prosthodontics : official journal of the American College of Prosthodontists [J Prosthodont] 2023 Jan; Vol. 32 (1), pp. 71-76. Date of Electronic Publication: 2022 Apr 04.
DOI: 10.1111/jopr.13506
Abstrakt: Purpose: The effect of annealing and firing cycle on the adaptation of cobalt-chromium (CoCr) restorations fabricated by additive manufacturing has been poorly documented. This study compared the marginal and internal fit of CoCr three-unit fixed dental prostheses before and after firing cycles.
Material and Methods: The first right maxillary premolar (MP) and molar (MM) on a typodont model, were prepared with a circumferential 1.2 mm chamfer, 2 mm occlusal reduction, and total taper of 8 degrees, to receive 3-unit fixed dental prostheses (FDP). After the framework design, 20 framework specimens were fabricated using CoCr metal powder by selective laser melting. The replica technique was used for marginal and internal fit measurements in mesiodistal and buccolingual planes. The specimens were submitted to an annealing process, and to ceramic firing protocol. Measurements were repeated after each firing cycle. The data were compared by using Levene test, t-test, and analysis of variance (ANOVA) (α = 0.05).
Results: A significant difference was found in the total intaglio surface discrepancy between the 3 treatments. The annealing treatment induced a statistical difference in the discrepancy value compared to the as printed state (p = 0.028). A significant difference was detected between the initial manufacturing phase and the ceramic layering firing cycle (p = 0.003).
Conclusions: Firing cycles induced an alteration of the frameworks adaptation.
(© 2022 by the American College of Prosthodontists.)
Databáze: MEDLINE
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