Development of Biocompatible Y-Stabilized ZrO2 Fabricated by Spark Plasma Sintering

2012 ◽  
Vol 86 ◽  
pp. 17-21 ◽  
Author(s):  
H. Sakai ◽  
Teruo Asaoka
Keyword(s):  
Bone Tissue ◽  
Tetragonal Zirconia ◽  
High Strength ◽  
The Body ◽  
Apatite Layer ◽  
Material Surface ◽  
Zirconia Ceramics ◽  
Hip Prostheses ◽  
Plasma Sintering

Due to the merits of zirconia ceramics such as high strength, toughness, abrasion resistance, and chemical stability in vivo, yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) are currently used in the femoral head of hip prostheses. However, this material has a limited applications range because it is a bioinert material that does not interact with bone tissue and thus does not easily integrate directly in the bone. Therefore, we need to add different material’s layer which enables in vivo formation of bone-like apatite layer that exhibits bioactivity , composite compound bioactive ceramics, and facilitates interactions and integration in bone tissue. In addition, by developing a surface structure that enhances mechanical bonding, this material can be expected to be used as an alternative aggregate under load bearing conditions. In the present study, various method were carried out with the objective of controlling interactions between zirconia ceramics and the body such as structural design of the material surface, addition of bioactivity using reagents treatment, confirmation of formation of the apatite layer using immersion in simulated body fluid, wettability testing and develop structure with mechanical properties equal to bone strength.

Addition of Surface Function to Zirconia for Biomaterial Use

2008 ◽  
Vol 57 ◽  
pp. 139-143 ◽  
Author(s):  
N. Koide ◽  
K. Suzuki ◽  
M. Tsuda ◽  
Teruo Asaoka
Keyword(s):  
Bone Tissue ◽  
Tetragonal Zirconia ◽  
High Strength ◽  
Limited Range ◽  
The Body ◽  
Apatite Layer ◽  
Material Surface ◽  
Zirconia Ceramics ◽  
Hip Prostheses

Due to the merits of zirconia ceramics such as high strength, toughness, and abrasion resistance, as well as chemical stability in vivo, yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) are currently used in the femoral head of hip prostheses. However, this material has a limited range of use because it is a bioinert material that does not interact with bone tissue and thus does not easily integrate directly with bone. Therefore, addition of a material surface that enables the in vivo formation of a bone-like apatite layer that exhibits bioactivity and facilitates interactions and integration with bone tissue is desired. In addition, by developing a surface structure that enhances mechanical bonding, this material can be expected to be used as an alternative aggregate under load bearing conditions. In the present study, structural design of the material surface, addition of bioactivity using reagents treatment, confirmation of formation of the apatite layer using immersion in simulated body fluid, mechanical assessment, and wettability testing were conducted with the objective of controlling interactions between zirconia ceramics and the body.

scholarly journals Monolithic Zirconia: An Update to Current Knowledge. Optical Properties, Wear, and Clinical Performance

2019 ◽  
Vol 7 (3) ◽  
pp. 90 ◽  
Author(s):  
Eleana Kontonasaki ◽  
Athanasios E. Rigos ◽  
Charithea Ilia ◽  
Thomas Istantsos
Keyword(s):  
Clinical Performance ◽  
Current Knowledge ◽  
High Strength ◽  
Wear Properties ◽  
Zirconia Ceramics ◽  
Term Survival ◽  
Monolithic Zirconia

The purpose of this paper was to update the knowledge concerning the wear, translucency, as well as clinical performance of monolithic zirconia ceramics, aiming at highlighting their advantages and weaknesses through data presented in recent literature. New ultra-translucent and multicolor monolithic zirconia ceramics present considerably improved aesthetics and translucency, which, according to the literature reviewed, is similar to those of the more translucent lithium disilicate ceramics. A profound advantage is their high strength at thin geometries preserving their mechanical integrity. Based on the reviewed articles, monolithic zirconia ceramics cause minimal wear of antagonists, especially if appropriately polished, although no evidence still exists regarding the ultra-translucent compositions. Concerning the survival of monolithic zirconia restorations, the present review demonstrates the findings of the existing short-term studies, which reveal promising results after evaluating their performance for up to 5 or 7 years. Although a significant increase in translucency has been achieved, new translucent monolithic zirconia ceramics have to be further evaluated both in vitro and in vivo for their long-term potential to preserve their outstanding properties. Due to limited studies evaluating the wear properties of ultra-translucent material, no sound conclusions can be made, whereas well-designed clinical studies are urgently needed to enlighten issues of prognosis and long-term survival.

scholarly journals Gelcast Zirconia Ceramics With High Strength and Simultaneously High Translucency for Dental Applications

2021 ◽  
Author(s):  
Jaroslav Kastyl ◽  
Zdenek Chlup ◽  
Vaclav Pouchly ◽  
Lu Song ◽  
Erik Scasnovic ◽  
...  
Keyword(s):  
Tetragonal Zirconia ◽  
High Strength ◽  
Processing Method ◽  
Density Structure ◽  
Zirconia Ceramics ◽  
Thick Sample ◽  
Dental Restorations ◽  
Structure Surface ◽  
Dental Applications ◽  
Very High

Abstract Translucent zirconia represents a favourite material for monolithic ceramic dental restorations. However, materials approaches employed so far to improve the translucency of zirconia ceramics are accompanied by a significant decline in strength. Thus, we aimed to develop dental 3Y-TZP ceramics that can provide excellent strength and, simultaneously, enhanced translucency. In this investigation, machinable tetragonal zirconia ceramics based on fine mesostructured zirconia particles stabilized with 3 mol% of yttria and prepared by the gelcasting processing method were developed. Properties of sintered samples were characterised, namely: shrinkage, density, structure, surface roughness, hardness, biaxial strength, and total forward transmittance. Zirconia ceramics with an average biaxial strength of 1184 MPa and a total forward transmittance of 46.7% for a 0.5 mm thick sample at a wavelength of 600 nm were obtained. These ceramics exhibited homogeneous structure with grains sizes up to 620 nm and purely tetragonal phase composition. The developed ceramics provided a favourable combination of high translucency comparable even with the mixed cubic/tetragonal structure of a common 4Y-TZP, and very high strength that is achievable only in the pure tetragonal 3Y-TZP.

scholarly journals Natural and Synthetic Polymers for Bone Scaffolds Optimization

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 905 ◽  
Author(s):  
Francesca Donnaloja ◽  
Emanuela Jacchetti ◽  
Monica Soncini ◽  
Manuela T. Raimondi
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue ◽  
Bone Cells ◽  
The Body ◽  
Bone Tissue Regeneration ◽  
In Vivo Models ◽  
Polymeric Scaffold ◽  
Technology Improvement

Bone tissue is the structural component of the body, which allows locomotion, protects vital internal organs, and provides the maintenance of mineral homeostasis. Several bone-related pathologies generate critical-size bone defects that our organism is not able to heal spontaneously and require a therapeutic action. Conventional therapies span from pharmacological to interventional methodologies, all of them characterized by several drawbacks. To circumvent these effects, tissue engineering and regenerative medicine are innovative and promising approaches that exploit the capability of bone progenitors, especially mesenchymal stem cells, to differentiate into functional bone cells. So far, several materials have been tested in order to guarantee the specific requirements for bone tissue regeneration, ranging from the material biocompatibility to the ideal 3D bone-like architectural structure. In this review, we analyse the state-of-the-art of the most widespread polymeric scaffold materials and their application in in vitro and in vivo models, in order to evaluate their usability in the field of bone tissue engineering. Here, we will present several adopted strategies in scaffold production, from the different combination of materials, to chemical factor inclusion, embedding of cells, and manufacturing technology improvement.

Correlation between Structural Properties and In Vivo Biocompatibility of Alumina/Zirconia Bioceramics

2011 ◽  
Vol 493-494 ◽  
pp. 1-6 ◽  
Author(s):  
Simona Cavalu ◽  
Viorica Simon ◽  
Cristian Ratiu ◽  
I. Oswald ◽  
R. Gabor ◽  
...  
Keyword(s):  
Animal Model ◽  
Structural Properties ◽  
Wistar Rats ◽  
Histological Analysis ◽  
Structural Characteristics ◽  
Zirconia Ceramics ◽  
Plasma Sintering ◽  
In Vivo Tests ◽  
Spark Plasma

The aim of our study is the characterization and comparison of structural properties of two novel alumina/zirconia ceramics prepared by Spark Plasma Sintering and biocompatibility evaluation by using an animal model (Wistar rats). SEM, XRD and FTIR spectroscopic results are reported for structural characteristics. In vivo tests demonstrated the biocompatibility and osseointegration of the composites by complementary SEM and histological analysis of the defects in rat femur respectively the connective tissue.

Environmental Phase Stability of Ceramics Composite for Hip Prostheses in Presence of Surface Damage

2007 ◽  
Vol 361-363 ◽  
pp. 783-786 ◽  
Author(s):  
Kiyotaka Yamada ◽  
Giuseppe Pezzotti
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Human Body ◽  
Phase Stability ◽  
Surface Damage ◽  
Material Surface ◽  
Hip Prostheses ◽  
M Phase ◽  
Alumina Matrix Composite

Alumina matrix composite (AMC) has been widely used for artificial hip and knee joints because of its phase stability in human body and its excellent wear resistance. The excellent mechanical properties of strength and fracture toughness of zirconia materials are well known to be closely related to stress-induced transformation from the tetragonal to the monoclinic phase, which is accompanied with 4% volume increase of the zirconia crystal cell. However, it is also to be considered that the material is prone to low temperature aging degradation (LTAD) under hydrothermal environment, like in the human body. This LTAD is influenced by the tetragonal to the monoclinic (t-m) phase transformation. T-m transformation also induces the formation of microcracks at the material surface, and an increase in surface. Microcracking leads to a decrease of mechanical properties, and could explain the failure of implants after some years in vivo [1, 2] .Therefore, it is very important to study how to prevent phase transformation in zirconia components. Transformed monoclinic zirconia percentage can be experimentally measured by Raman spectroscopy and the residual stress distribution, which is related to phase transformation, can be determined by a non-destructive piezo-spectroscopic analysis. In this paper, we attempted to evaluate it from both stress and mechanical properties points of view by confocal Raman and fluorescence spectroscopy.

scholarly journals A pilot study on the use of 3D printers in veterinary medicine

2021 ◽  
Vol 14 (3) ◽  
pp. 159-164
Author(s):  
Leonardo Leonardi ◽  
◽  
Roberto Marsili ◽  
Enrico Bellezza ◽  
Giovanni Angeli ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Bone Tissue ◽  
Three Dimensional ◽  
The Body ◽  
Porous Scaffolds ◽  
Layer By Layer ◽  
Three Dimensional Objects ◽  
Cellular Attachment

Additive manufacturing (AM) is the process of joining materials to create layer-by-layer three-dimensional objects using a 3D printer from a digital model. The great advantage of Additive Manufacturing is to allow a freer design than traditional processes. The development of additive manufacturing processes has permitted to optimize the production of the customized product through the modeling of the geometry and the knowledge of the morphometric parameters of the body structures. 3D printing has revolutionized the field of Regenerative Medicine because, starting from computerized tomography (CT) images and using traditional materials such as plastic and metals, it can provide customized prostheses for each patient, which adapt perfectly to the needs of the subject and act as structures support. 3D printing allows you to print three-dimensional porous scaffolds with a precise shape and chemical composition suitable for medical and veterinary use. Some of these scaffolds are biodegradable and appear to be ideal for bone tissue engineering. In fact, they are able to simulate extracellular matrix properties that allow mechanical support, favoring mechanical interactions and providing a model for cellular attachment and in vivo stimulation of bone tissue formation.

scholarly journals Ceramic Packaging in Neural Implants

2020 ◽  
Author(s):  
Konlin Shen ◽  
Michel M. Maharbiz
Keyword(s):  
Thin Film ◽  
Traditional Approach ◽  
Semiconductor Industry ◽  
High Strength ◽  
Ceramic Materials ◽  
The Body ◽  
Medical Implants ◽  
Neural Implants ◽  
Housing Materials

AbstractThe lifetime of neural implants is strongly dependent on packaging due to the aqueous and biochemically aggressive nature of the body. Over the last decade, there has been a drive towards neuromodulatory implants which are wireless and approaching millimeter-scales with increasing electrode count. A so-far unrealized goal for these new types of devices is an in-vivo lifetime comparable to a sizable fraction of a healthy patient’s lifetime (>10-20 years). Existing, approved medical implants commonly encapsulate components in metal enclosures (e.g. titanium) with brazed ceramic inserts for electrode feedthrough. It is unclear how amenable the traditional approach is to the simultaneous goals of miniaturization, increased channel count, and wireless communication. Ceramic materials have also played a significant role in traditional medical implants due to their dielectric properties, corrosion resistance, biocompatibility, and high strength, but are not as commonly used for housing materials due to their brittleness and the difficulty they present in creating complex housing geometries. However, thin film technology has opened new opportunities for ceramics processing. Thin films derived largely from the semiconductor industry can be deposited and patterned in new ways, have conductivities which can be altered during manufacturing to provide conductors as well as insulators, and can be used to fabricate flexible substrates. In this review, we give an overview of packaging for neural implants, with an emphasis on how ceramic materials have been utilized in medical device packaging, as well as how ceramic thin film micromachining and processing may be further developed to create truly reliable, miniaturized, neural implants

Understanding the Effects of Thermal Elevations Associated With Orthopedic Intervention: An Experimental and Computational Investigation

2013 ◽  
Author(s):  
E. B. Dolan ◽  
T. J. Vaughan ◽  
G. L. Niebur ◽  
D. Tallon ◽  
L. M. McNamara
Keyword(s):  
Bone Tissue ◽  
Computational Models ◽  
Thermal Damage ◽  
Elevated Temperatures ◽  
Bone Cells ◽  
The Body ◽  
Surrounding Soft Tissue ◽  
Multi Scale ◽  
Orthopedic Surgeons

Specialized surgical cutting instruments are required to provide orthopedic surgeons with access to joints of the body, without causing extensive harm to native tissue, thus enhancing post-operative outcome. Orthopaedic intervention inevitably exposes bone tissue to elevated temperatures due to mechanical abrasion. Elevated temperatures lead to thermal necrosis and apoptosis of bone cells, surrounding soft tissue, bone marrow and stem cells crucial for postoperative healing (1–4). Thermally damaged bone tissue is subsequently resorbed and in severe cases replaced by connective tissue (2, 5) Bone thermal damage occurs when the local temperature exceeds a thermal threshold, largely recognised as ≥47°C (4, 6). Furthermore, it has been proposed that the area of bone to experience thermal damage is directly proportional to the duration of exposure to the heat source (7, 8). However, precise thermal elevations occurring throughout bone during surgical cutting are not well defined. It is also unclear whether temperatures generated in osteocytes in vivo are sufficient to induce cellular responses. Experimental analysis of temperature generation throughout bone is challenging due to its complex heterogeneous composition. There is a specific need for advanced 3D computational models that incorporate multi-scale variability in both bone tissue composition and thermal properties to predict how organ level thermal elevations are distributed throughout bone cells and tissue during orthopaedic cutting procedures.

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