Mechanical properties, aging stability and translucency of speed-sintered zirconia for chairside restorations.

Autor: Cokic SM; KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium., Vleugels J; KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium., Van Meerbeek B; KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium. Electronic address: bart.vanmeerbeek@kuleuven.be., Camargo B; KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium., Willems E; KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium., Li M; KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium., Zhang F; KU Leuven (University of Leuven), Department of Oral Health Sciences, BIOMAT & UZ Leuven (University Hospitals Leuven), Dentistry, Leuven, Belgium; KU Leuven (University of Leuven), Department of Materials Engineering (MTM), Kasteelpark Arenberg 44, B-3001 Leuven, Belgium.
Jazyk: angličtina
Zdroj: Dental materials : official publication of the Academy of Dental Materials [Dent Mater] 2020 Jul; Vol. 36 (7), pp. 959-972. Date of Electronic Publication: 2020 Jun 01.
DOI: 10.1016/j.dental.2020.04.026
Abstrakt: Objective: To evaluate the performance of zirconia ceramics sintered in a speed sintering induction furnace by comprehensive understanding of their optical and mechanical properties, microstructure, phase composition and aging stability, in comparison to ceramics sintered in a conventional furnace.
Methods: Speed sintered (SS) Katana STML SS (Kuraray Noritake) (total thermal cycle/sintering time/dwell temperature: 30min/16min/1560°C) and CEREC Zirconia (CEREC Zr SS ) (Dentsply Sirona) (15min/2min/1578°C) were compared to conventionally sintered (CS) Katana STML CS (6.8h/2h/1550°C) and inCoris TZI CS (4h/2h/1510°C). The translucency parameter (TP) and contrast ratio (CR) were measured with a spectrophotometer. The chemical composition of the materials was determined by XRF and phase composition was characterized using XRD. Hydrothermal aging behavior was evaluated by measuring the tetragonal-to-monoclinic ZrO 2 phase transformation after accelerated hydrothermal aging in steam at 134°C. The indentation fracture toughness, Vickers hardness and biaxial strength of the sintered ceramics were assessed.
Results: Speed and conventionally sintered zirconia revealed similar density, microstructure, average strength and hydrothermal aging stability. Both Katana STML SS/CS 5Y-PSZ ceramics were characterized with a higher content of cubic phase (≈53wt%), which resulted in a higher amount of Y 2 O 3 in the remaining tetragonal ZrO 2 phases compared to the 3Y-TZP CEREC Zr SS and inCoris TZI CS (8 and 20wt%, respectively). The sintering program did not affect the hydrothermal aging behavior of Katana STML SS and CEREC Zr SS . TP of Katana STML SS (TP≈32) was not affected by speed sintering, while the translucency of CEREC Zr SS (TP=14) was significantly reduced. Hardness, fracture toughness and Weibull characteristic strength of Katana STML SS and CEREC Zr SS also reached the optimal level, but speed sintering substantially lowered their mechanical reliability.
Significance: Speed sintering of 3Y-TZP and 5Y-PSZ in a speed sintering induction oven appeared suitable for clinical applications. However, further studies should focus on improving of translucency and mechanical reliability of the speed-sintered zirconia ceramics.
(Copyright © 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: