Electrical Polarization Depresses Low Temperature Degradation and Promotes Bioactivity of Chemically Treated Yttria-Stabilized Zirconia

2011 ◽  
Vol 493-494 ◽  
pp. 11-15
Author(s):  
Miho Nakamura ◽  
Naohiro Horiuchi ◽  
Akiko Nagai ◽  
Kimihiro Yamashita
Keyword(s):  
Oxygen Vacancies ◽  
Water Adsorption ◽  
Alkaline Treatment ◽  
Yttria Stabilized Zirconia ◽  
Charged Surface ◽  
Stabilized Zirconia ◽  
Electrical Polarization ◽  
Oxide Ions ◽  
Positively Charged

Because of its excellent mechanical properties, yttria-stabilized zirconia is currently used as an orthopedic and dental material. In this study, we have improved the bioactivity of yttria-stabilized zirconia by a combination of electrical polarization and chemical treatment. The phase transformation from tetragonal to monoclinic ZrO2 after alkaline treatment was inhibited on positively-charged yttria-stabilized zirconia surfaces compared with negatively charged and conventional surfaces. During polarization, some oxide ions move from the positively-charged surface to the negatively charged surface, leading to an increase in oxygen vacancies on the positive surface and hence greater formation of Zr-OH when this surface was exposed to alkaline solution. This then reduced the water adsorption at this surface and consequently reduced the rate of cleavage of Zr-O-Zr bonds. The bioactivity was assessed by immersing the samples in simulated body fluid and evaluating the growth of apatite on the surfaces. The combination of polarization and alkaline treatment increased the bioactivity in vitro.

scholarly journals The Anchorage of Bone Cells onto an Yttria-Stabilized Zirconia Surface with Mild Nano-Micro Curved Profiles

2020 ◽  
Vol 8 (4) ◽  
pp. 127
Author(s):  
Susanne Staehlke ◽  
Armin Springer ◽  
Thomas Freitag ◽  
Jakob Brief ◽  
J. Barbara Nebe
Keyword(s):  
Matrix Protein ◽  
Bone Cells ◽  
Cell Attachment ◽  
Yttria Stabilized Zirconia ◽  
Extracellular Matrix Protein ◽  
Cell Phenotype ◽  
Ros Generation ◽  
Stabilized Zirconia ◽  
Dental Surgery

The high biocompatibility, good mechanical properties, and perfect esthetics of ceramic dental materials motivate investigation into their suitability as an endosseous implant. Osseointegration at the interface between bone and implant surface, which is a criterion for dental implant success, is dependent on surface chemistry and topography. We found out earlier that osteoblasts on sharp-edged micro-topographies revealed an impaired cell phenotype and function and the cells attempted to phagocytize these spiky elevations in vitro. Therefore, micro-structured implants used in dental surgery should avoid any spiky topography on their surface. The sandblasted, acid-etched, and heat-treated yttria-stabilized zirconia (cer.face®14) surface was characterized by scanning electron microscopy and energy dispersive X-ray. In vitro studies with human MG-63 osteoblasts focused on cell attachment and intracellular stress level. The cer.face 14 surface featured a landscape with nano-micro hills that was most sinusoidal-shaped. The mildly curved profile proved to be a suitable material for cell anchorage. MG-63 cells on cer.face 14 showed a very low reactive oxygen species (ROS) generation similar to that on the extracellular matrix protein collagen I (Col). Intracellular adenosine triphosphate (ATP) levels were comparable to Col. Ceramic cer.face 14, with its sinusoidal-shaped surface structure, facilitates cell anchorage and prevents cell stress.

Environmental Effect on the Crack Behavior of Yttria-Stabilized Zirconia During Laser Drilling

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Hong Shen ◽  
Juan Jiang ◽  
Decai Feng ◽  
Chen Xing ◽  
Xiaofeng Zhao ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Phase Transformation ◽  
Environmental Effect ◽  
Monoclinic Phase ◽  
Oxygen Vacancies ◽  
High Stress ◽  
Laser Drilling ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Crack Behavior

The crack behaviors of yttrium-stabilized zirconia during laser drilling in air, vacuum, and water environments were investigated. Due to the high stress and low fracture toughness induced by tetragonal-monoclinic phase transformation, tremendous cracks occur during drilling in air. Contrastly, cracks were reduced in vacuum drilling since the phase transformation was suppressed due to the generation of oxygen vacancies. By protection of water, no cracks were observed due to low stress and maintained fracture toughness. The crack mechanisms in different drilling media were discussed.

Elaboration of Sol-Gel Derived Hydroxyapatite / Yttria Stabilized Zirconia Composite Coatings Obtained for Biomedical Application

2011 ◽  
Vol 312-315 ◽  
pp. 894-899
Author(s):  
Sahar Salehi ◽  
Mohammad Hosseien Fathi
Keyword(s):  
Grain Size ◽  
Crystallite Size ◽  
Grain Growth ◽  
Biomedical Application ◽  
Composite Coatings ◽  
Sol Gel ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Nanostructured Composite

In this study, nanostructured composite coatings of hydroxyapatite (HA)/ 30wt% yttria stabilized zirconia (YSZ) coatings containing 0, 3, 5, and 8 mol% Y2O3 (namely; HA-0YSZ, HA-3YSZ, HA-5YSZ, and HA-8YSZ) were successfully synthesized using the sol-gel method. The crystallite size of the coating was about ~44-58 nm for tetragonal and cubic zirconia grain size and 75-87 nm for hydroxyapatite grain size. Crack-free and homogeneous HA-YSZ composite coatings were obtained with no observable defects. The uniform distribution of zirconia particles in a composite would be highly beneficial for obtaining homogeneous coatings of HA-YSZ film and would hinder grain growth of HA phase during calcinations. In vitro evaluation in 0.9% NaCl showed that Ca2+ dissolution rate of composite coatings was lower than pure HA coatings.

In vitro evaluation of an yttria-stabilized zirconia reinforced nano-hydroxyapatite/polyamide 66 ternary biomaterial: biomechanics, biocompatibility and bioactivity

RSC Advances ◽  
2016 ◽  
Vol 6 (115) ◽  
pp. 114086-114095 ◽  
Author(s):  
Yuling Li ◽  
Hong Li ◽  
Jing Zhang ◽  
Weikang Zhao ◽  
Jieliang Shen ◽  
...  
Keyword(s):  
Tetragonal Zirconia ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Polyamide 66 ◽  
In Vitro Evaluation

The characterization of a novel ternary biomaterial composed of nano-hydroxyapatite/polyamide 66/yttria-stabilized tetragonal zirconia.

scholarly journals A continuum model for yttria-stabilized zirconia incorporating triple phase boundary, lattice structure and immobile oxide ions

2019 ◽  
Vol 23 (10) ◽  
pp. 2907-2926 ◽  
Author(s):  
Petr Vágner ◽  
Clemens Guhlke ◽  
Vojtěch Miloš ◽  
Rüdiger Müller ◽  
Jürgen Fuhrmann
Keyword(s):  
Phase Boundary ◽  
Continuum Model ◽  
Lattice Structure ◽  
Surface Reactions ◽  
Yttria Stabilized Zirconia ◽  
Cyclic Voltammograms ◽  
Stabilized Zirconia ◽  
Triple Phase Boundary ◽  
The Impact ◽  
Oxide Ions

Abstract A continuum model for yttria-stabilized zirconia (YSZ) in the framework of non-equilibrium thermodynamics is developed. Particular attention is given to (i) modeling of the YSZ-metal-gas triple phase boundary, (ii) incorporation of the lattice structure and immobile oxide ions within the free energy model and (iii) surface reactions. A finite volume discretization method based on modified Scharfetter-Gummel fluxes is derived in order to perform numerical simulations. The model is used to study the impact of yttria and immobile oxide ions on the structure of the charged boundary layer and the double layer capacitance. Cyclic voltammograms of an air-half cell are simulated to study the effect of parameter variations on surface reactions, adsorption and anion diffusion.

Effect of different grinding protocols on surface characteristics and fatigue behavior of yttria-stabilized zirconia polycrystalline: An in vitro study

2020 ◽  
Vol 124 (4) ◽  
pp. 486.e1-486.e8 ◽  
Author(s):  
Lívia Fiorin ◽  
Izabela C.M. Moris ◽  
Adriana C.L. Faria ◽  
Ricardo F. Ribeiro ◽  
Renata C.S. Rodrigues
Keyword(s):  
Fatigue Behavior ◽  
In Vitro Study ◽  
Surface Characteristics ◽  
Yttria Stabilized Zirconia ◽  
Vitro Study ◽  
Stabilized Zirconia

scholarly journals Use of CuNi/YSZ and CuNi/SDC Catalysts for the Reverse Water Gas Shift Reaction

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Maxime Lortie ◽  
Rima J. Isaifan
Keyword(s):  
Oxygen Vacancies ◽  
Yttria Stabilized Zirconia ◽  
Water Gas Shift ◽  
Water Gas Shift Reaction ◽  
Stabilized Zirconia ◽  
Reverse Water Gas Shift ◽  
Partial Pressures ◽  
Modified Polyol Method ◽  
Shift Reaction ◽  
Water Gas

Cu50Ni50 nanoparticles were synthesized using a modified polyol method and deposited on samarium-doped ceria, SDC, and yttria-stabilized zirconia, YSZ, supports to form reverse water-gas shift, RWGS, catalysts. The best CO yields, obtained with the Cu50Ni50/SDC catalyst, were about 90% of the equilibrium CO yields. In contrast CO yields using Pt/SDC catalysts were equal to equilibrium CO yields at 700°C. Catalyst selectivity to CO was 100% at hydrogen partial pressures equal to CO2 partial pressures, 1 kPa, and decreased as methane was formed when the hydrogen partial pressure was 2 kPa or greater. The reaction results were explained using a combination of Eley-Rideal and Langmuir-Hinshelwood mechanisms that involved adsorption on the metal surface and the concentration of oxygen vacancies in the support. Finally the Cu50Ni50/SDC catalyst was found to be thermally stable for 48 hours at 600/700°C.

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