TY - JOUR
T1 - Influence of crystalline phase transformation induced by airborne-particle abrasion and low-temperature degradation on mechanical properties of dental zirconia ceramics stabilized with over 5 mol% yttria
AU - Nakamura, Keisuke
AU - Tarkeshi, Aria
AU - Niklasson, Alexander
AU - Shishido, Shunichi
AU - Svanborg, Per
AU - Barkarmo, Sargon
AU - Örtengren, Ulf
N1 - Funding Information:
The authors would like to sincerely thank the following companies for providing materials for this study: Kuraray Noritake Dental Inc. Tokyo, Japan and 3M/ESPE, St. Paul, USA. We would also like to express our sincere gratitude to Professor Ann Wennerberg for her advice during the interferometry measurements and to Petra Hammarström Johansson (research assistant) for her assistance in the laboratory work. This work was partly supported by the JSPS KAKENHI Grant-in-Aid for Scientific Research (C) [grant number 19K10239].
Funding Information:
The authors would like to sincerely thank the following companies for providing materials for this study: Kuraray Noritake Dental Inc., Tokyo, Japan and 3M/ESPE, St. Paul, USA. We would also like to express our sincere gratitude to Professor Ann Wennerberg for her advice during the interferometry measurements and to Petra Hammarström Johansson (research assistant) for her assistance in the laboratory work. This work was partly supported by the JSPS KAKENHI Grant-in-Aid for Scientific Research (C) [grant number 19K10239 ].
Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2022/1
Y1 - 2022/1
N2 - Monolithic dental prostheses fabricated from 5 mol% yttria-stabilized zirconia (5YZ) have been developed to improve the translucency of conventional 3 mol% yttria-stabilized zirconia. In this study, we aimed to evaluate the influence of airborne-particle abrasion (APA) and low-temperature degradation (LTD) on the mechanical properties of 5YZ in association with the crystalline phase transformation. In total, 120 disc-shaped specimens of two brands of 5YZ (Lava Esthetic and Katana UTML) were prepared. The specimens were divided into four groups (n = 15 for each group): (i) control, (ii) APA, (iii) LTD, and (iv) APA + LTD groups. APA was performed with 50 μm alumina particles, and LTD was induced by autoclaving at 134 °C for 50 h. The biaxial flexural strength of the specimens was assessed using a piston-on-three-ball test according to ISO 6872:2015, and Vickers hardness was determined using a microhardness tester. The crystalline phase was analyzed by the Rietveld refinement of X-ray diffraction patterns. APA significantly increased the flexural strength of the Lava Esthetic specimens, whereas LTD hardly affected the strength of both materials. APA and APA + LTD significantly increased the Vickers hardness of both materials. According to Rietveld analysis, the pseudocubic phase was predominant in both materials, i.e., 66 mass% and 81 mass% in the Lava Esthetic and Katana UTML specimens, respectively. APA induced the rhombohedral phase at approximately 37 mass% in both materials, while LTD induced the monoclinic phase at 2.8 mass% in the Lava Esthetic specimens and 0.9 mass% in the Katana UTML specimens. APA + LTD weakly affected the amount of the rhombohedral phase but slightly increased the amount of the monoclinic phase. These findings suggest that APA may improve the mechanical properties of 5YZ, particularly hardness, via the generation of the rhombohedral phase. In contrast, the influence of LTD on the mechanical and microstructural properties of 5YZ was limited.
AB - Monolithic dental prostheses fabricated from 5 mol% yttria-stabilized zirconia (5YZ) have been developed to improve the translucency of conventional 3 mol% yttria-stabilized zirconia. In this study, we aimed to evaluate the influence of airborne-particle abrasion (APA) and low-temperature degradation (LTD) on the mechanical properties of 5YZ in association with the crystalline phase transformation. In total, 120 disc-shaped specimens of two brands of 5YZ (Lava Esthetic and Katana UTML) were prepared. The specimens were divided into four groups (n = 15 for each group): (i) control, (ii) APA, (iii) LTD, and (iv) APA + LTD groups. APA was performed with 50 μm alumina particles, and LTD was induced by autoclaving at 134 °C for 50 h. The biaxial flexural strength of the specimens was assessed using a piston-on-three-ball test according to ISO 6872:2015, and Vickers hardness was determined using a microhardness tester. The crystalline phase was analyzed by the Rietveld refinement of X-ray diffraction patterns. APA significantly increased the flexural strength of the Lava Esthetic specimens, whereas LTD hardly affected the strength of both materials. APA and APA + LTD significantly increased the Vickers hardness of both materials. According to Rietveld analysis, the pseudocubic phase was predominant in both materials, i.e., 66 mass% and 81 mass% in the Lava Esthetic and Katana UTML specimens, respectively. APA induced the rhombohedral phase at approximately 37 mass% in both materials, while LTD induced the monoclinic phase at 2.8 mass% in the Lava Esthetic specimens and 0.9 mass% in the Katana UTML specimens. APA + LTD weakly affected the amount of the rhombohedral phase but slightly increased the amount of the monoclinic phase. These findings suggest that APA may improve the mechanical properties of 5YZ, particularly hardness, via the generation of the rhombohedral phase. In contrast, the influence of LTD on the mechanical and microstructural properties of 5YZ was limited.
KW - 5 mol% yttria-stabilized zirconia
KW - Airborne-particle abrasion
KW - Biaxial flexural strength
KW - Crystalline structure
KW - Low-temperature degradation
KW - Monolithic zirconia
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U2 - 10.1016/j.jmbbm.2021.104890
DO - 10.1016/j.jmbbm.2021.104890
M3 - Article
C2 - 34673358
AN - SCOPUS:85117123361
SN - 1751-6161
VL - 125
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
M1 - 104890
ER -