TY - JOUR
T1 - New multi-layered zirconias
T2 - Composition, microstructure and translucency
AU - Kolakarnprasert, Nantawan
AU - Kaizer, Marina R.
AU - Kim, Do Kyung
AU - Zhang, Yu
N1 - Funding Information:
Funding was provided by the U.S. National Institutes of Health / National Institute of Dental and Craniofacial Research (grants No. R01DE026772 and R01DE026279 ). The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article.
Publisher Copyright:
© 2019 The Academy of Dental Materials
PY - 2019/5
Y1 - 2019/5
N2 - Objectives: To fully realize the range of indication and clinical advantages of the new multi-layered zirconias, a comprehensive understanding of their chemical composition, microstructure, low temperature degradation (LTD) resistance, and translucency properties is paramount. Methods: A zirconia system (Katana, Kuraray Noritake), including 3 distinct grades of multi-layered zirconias, was selected for study: Ultra Translucent Multi-layered zirconia (UTML), Super Translucent Multi-layered zirconia (STML), and Multi-layered zirconia (ML). For different materials and their individual layers, the chemical composition, zirconia phase fractions, and microstructure were determined by X-ray fluorescence (XRF), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Also, their resistance to LTD and translucency properties were characterized. Results: Our findings revealed no major differences amongst layers, but the 3 materials were very distinct―UTML: 5Y-PSZ (5 mol% yttria-partially-stabilized zirconia) with ˜75 wt% cubic content and a 4.05 (±0.85) μm average grain size, STML: 4Y-PSZ with ˜65 wt% cubic content and a 2.81 (±0.17) μm average grain size, and ML: 3Y-PSZ with <50 wt% cubic content and a 0.63 (±0.03) μm average grain size. After water aging at 120 °C for 12 h, greater monoclinic content was found in ML. UTML and STML did not show detectable monoclinic phase. The translucency was similar among layers, and also between UTML and STML, which were superior to ML. Significance: For each multi-layered zirconia grades, the layers are only differed in pigment types and contents, which yield remarkably natural shade gradients. Also, despite the significant compositional difference between STML and UTML, both materials showed similar translucencies.
AB - Objectives: To fully realize the range of indication and clinical advantages of the new multi-layered zirconias, a comprehensive understanding of their chemical composition, microstructure, low temperature degradation (LTD) resistance, and translucency properties is paramount. Methods: A zirconia system (Katana, Kuraray Noritake), including 3 distinct grades of multi-layered zirconias, was selected for study: Ultra Translucent Multi-layered zirconia (UTML), Super Translucent Multi-layered zirconia (STML), and Multi-layered zirconia (ML). For different materials and their individual layers, the chemical composition, zirconia phase fractions, and microstructure were determined by X-ray fluorescence (XRF), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Also, their resistance to LTD and translucency properties were characterized. Results: Our findings revealed no major differences amongst layers, but the 3 materials were very distinct―UTML: 5Y-PSZ (5 mol% yttria-partially-stabilized zirconia) with ˜75 wt% cubic content and a 4.05 (±0.85) μm average grain size, STML: 4Y-PSZ with ˜65 wt% cubic content and a 2.81 (±0.17) μm average grain size, and ML: 3Y-PSZ with <50 wt% cubic content and a 0.63 (±0.03) μm average grain size. After water aging at 120 °C for 12 h, greater monoclinic content was found in ML. UTML and STML did not show detectable monoclinic phase. The translucency was similar among layers, and also between UTML and STML, which were superior to ML. Significance: For each multi-layered zirconia grades, the layers are only differed in pigment types and contents, which yield remarkably natural shade gradients. Also, despite the significant compositional difference between STML and UTML, both materials showed similar translucencies.
KW - Chemical composition
KW - Dental ceramics
KW - Low temperature degradation
KW - Microstructure
KW - Multi-layered zirconia
KW - Phase content
KW - Translucency properties
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U2 - 10.1016/j.dental.2019.02.017
DO - 10.1016/j.dental.2019.02.017
M3 - Article
C2 - 30853208
AN - SCOPUS:85062477220
SN - 0109-5641
VL - 35
SP - 797
EP - 806
JO - Dental Materials
JF - Dental Materials
IS - 5
ER -