scholarly journals In-vitro & In-vivo Investigation of the Silicon Nitride Ceramic Hip Implant’s Safety and Effectiveness Evaluation

2021 ◽  
Author(s):  
Xiangpeng Kong ◽  
Xiaosu Hu ◽  
Wei Chai
Keyword(s):  
Silicon Nitride ◽  
High Hardness ◽  
High Strength ◽  
Oxide Ceramic ◽  
Orthopaedic Implant ◽  
Silicon Nitride Ceramic ◽  
Hip Implant ◽  
Total Hip

Abstract Background: With regard to the ceramic hip joint implant, given the concerns in ceramic about the alumina brittleness and zirconia instability, is there any alternative material solution for the orthopaedic implant? Beyond the metastable oxide ceramics, along the echelon of advanced technical ceramics, looking at the non-oxide ceramic, the silicon nitride could be an excellent candidate for the joint implant’s application. The purpose of this study is to investigate the safety, effectiveness and to demonstrate the potential of this silicon nitride hip implant. Methods: According to the related ISO (International Organization for Standardization) standards, a series of in-vitro (nine) & in-vivo (five) tests, which had been accomplished for the aforementioned aim. Especially, the total hip replacement in pigs had been achieved, as per the authors’ knowledge, this is the first time to apply the THA (Total Hip Arthroplasty) in the big animal. Results: Refer to the ISO 6474-2, in comparison with the current monopolized German product, this silicon nitride ceramic hip implant has high strength, high hardness, excellent fracture toughness, lower density, better wear resistance, good biocompatibility, inherent stability, corrosion resistance and bioactivity, bone integration capability. Conclusions: This silicon nitride ceramic will be an admirable alternative solution with superior comprehensive property that can withstand the toughest conditions in the most demanding applications like in orthopedic and beyond.

Mechanical Properties of Si3N4 Ceramics Prepared by Nitrided Pressureless Sintered (NPS) Process

2007 ◽  
Vol 124-126 ◽  
pp. 1461-1464
Author(s):  
Chang Gyu Kang ◽  
Joong Gwun Park ◽  
Tae Won Kang ◽  
Chul Kim ◽  
Tae Woo Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silicon Nitride ◽  
Molten Aluminum ◽  
Continuous Process ◽  
High Hardness ◽  
High Strength ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Silicon Nitride Ceramic ◽  
Ceramic Components

As an alternative to degassing pipe and rotor blade using in molten aluminum industry, we investigate the mechanical properties of silicon nitride ceramic components prepared by nitrided pressureless sintered (NPS) process, which process is the continuous process of nitridation reaction process combined with pressureless sintering. Mechanical properties of silicon nitride prepared by NPS process with sintering additives of 5wt% Y2O3, 5wt% Al2O3 and 20wt% Si show high strength, >500 MPa, high hardness, 12.6 GPa, and superior damage tolerances with high fracture toughness, 9.8 MPam1/2.

Effects of multiscale porosity and pore interconnectivity on in vitro and in vivo degradation and biocompatibility of Fe-Mn-Cu scaffold

2021 ◽  
Author(s):  
Santanu Mandal ◽  
Viraj Rathod ◽  
Samit Kumar Nandi ◽  
Mangal Roy
Keyword(s):  
High Strength ◽  
Pore Interconnectivity ◽  
In Vivo Degradation

Iron (Fe) based scaffolds are promising candidates as degradable metallic scaffolds. High strength and ability to control the degradation with tailormade composition and porosity are specific advantages of these scaffolds....

UV Activated Copolymerization Coatings of Urethane Acrylates for Use in the Cosmetic Industry

2021 ◽  
Author(s):  
◽  
Zane Grigale-Soročina
Keyword(s):  
Color Constancy ◽  
Surface Hardness ◽  
High Strength ◽  
Polymerization Process ◽  
Component Selection ◽  
Materials Used ◽  
Pigmented Coatings

In the dissertation compositions of urethane diacrylates and monoacrylates have been studied, which when curing under the conditions of UV-activated copolymerization process meeting the requirements of cosmetic varnishes, form cross-linked structure coatings with high strength-deformation, surface hardness, surface light reflectance, adhesion and other parameters. The review of the literature summarizes information on the types of natural nail coatings and the basic components entering them. Restrictions on the choice of basic components entering the system are described. The effect of conditions and components on the natural nail is described. The materials used in the research are described in the methodological part of the work. The process of obtaining compositions is described. The research methods used are described: characterization of rheological properties of non-polymerized compositions, differential thermal analysis of polymerization process, determination of polymerization depth, determination of crosslinked part of polymerized systems, determination of yield tensile strength-deformation, coating surface hardness, surface gloss and surface wear, assessment of adhesion and its durability, in-vitro and in-vivo coating adhesion studies on natural nails, spectroscopic analysis of pigmented coatings and assessment of color constancy, comparison of coating compositions in terms of their functionality and effects on human health. In the experimental part of the work, methodologies for component selection, composite system formation and obtaining appropriate coatings have been developed. A methodology has been developed for the evaluation of the set of structures and properties of the obtained coatings. The influence of the chemical nature and content ratios of urethane diacrylates and monoacrylates suitable for the formation of separate cosmetic coatings on the indicators of cross-linked structures formed in the process of UV-activated copolymerization and the corresponding indicators of coating properties has been studied. The influence of individual additives on the properties of cross-linked coatings, their adhesion to the surface and the durability of the coating at removal process has been evaluated.

Hot Rolling Steels and Super Alloys with Silicon Nitride Tools

2010 ◽  
Vol 65 ◽  
pp. 92-99
Author(s):  
R. Danzer
Keyword(s):  
Silicon Nitride ◽  
Fatigue Cracks ◽  
High Strength ◽  
Ceramic Tool ◽  
Silicon Nitride Ceramic ◽  
Small Surface ◽  
Metal Parts ◽  
Improved Performance ◽  
Montanuniversität Leoben ◽  
Super Alloy

Tools for rolling steels and super alloys, which are nowadays in general made from steel or cemented carbides, suffer from wear and/or from surface cracking caused by thermal fatigue. New tools made from silicon nitride show improved performance in respect to thermal shock loading and wear. But their low toughness manifests also a high risk of brittle failure. Nevertheless the successful use of silicon nitride rolls with having more than a manifold lifetime (compared to the conventional solutions) has been reported in the last years [1 -3]. In this paper earlier work of the Institut für Struktur- und Funktionskeramik at Montanuniversität Leoben on highly loaded silicon nitride rolls is summarized, where the limits of the Application of silicon nitride rolling tools are discussed. On the extreme example of rolls for super alloy wire rolling the behaviour of small surface cracks in the roll track is discussed. It is shown that – for the investigated conditions - rolling high strength steel wires is manageable but rolling of super alloy wires will cause the growth of fatigue cracks, which may destroy the rolls after some tons of rolled wire. A not trivial problem to be solved is the connection of the ceramic tool with the metal parts of the roll stand. Thermal strains of the metal parts can be several times larger than those of the silicon nitride ceramic and can therefore cause very high thermal misfit strains, even if the heating of metal parts seems to be modest. This case is discussed on the example of a catastrophically failed ceramic tool. This clearly shows that not only the tool but also the joint of the tool to the rest of the machinery has to be designed carefully. In summary this work demonstrates that a successful use of silicon nitride ceramic tools for cold and hot forming of metals and alloys is possible.

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.

Ion release in ceramic bearings for total hip replacement: Results from an in vitro and an in vivo study

2017 ◽  
Vol 42 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Jan Philippe Kretzer ◽  
Ulrike Mueller ◽  
Marcus R. Streit ◽  
Hartmuth Kiefer ◽  
Robert Sonntag ◽  
...  
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
In Vivo Study ◽  
Ion Release ◽  
Total Hip

scholarly journals Reproduction of fretting wear at the stem—cement interface in total hip replacement

2007 ◽  
Vol 221 (8) ◽  
pp. 963-971 ◽  
Author(s):  
L Brown ◽  
H Zhang ◽  
L Blunt ◽  
S Barrans
Keyword(s):  
Bone Cement ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Fatigue Cracks ◽  
Cement Mantle ◽  
Fretting Wear ◽  
Cement Interface ◽  
Total Hip

The stem-cement interface experiences fretting wear in vivo due to low-amplitude oscillatory micromotion under physiological loading, as a consequence it is considered to play an important part in the overall wear of cemented total hip replacement. Despite its potential significance, in-vitro simulation to reproduce fretting wear has seldom been attempted and even then with only limited success. In the present study, fretting wear was successfully reproduced at the stem-cement interface through an in-vitro wear simulation, which was performed in part with reference to ISO 7206-4: 2002. The wear locations compared well with the results of retrieval studies. There was no evidence of bone cement transfer films on the stem surface and no fatigue cracks in the cement mantle. The cement surface was severely damaged in those areas in contact with the fretting zones on the stem surface, with retention of cement debris in the micropores. Furthermore, it was suggested that these micropores contributed to initiation and propagation of fretting wear. This study gave scope for further comparative study of the influence of stem geometry, stem surface finish, and bone cement brand on generation of fretting wear.

Sign in / Sign up

Export Citation Format

Share Document