scholarly journals Repeated Exposure of Nanostructured Titanium to Osteoblasts with Respect to Peri-Implantitis

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 697
Author(s):  
Vaclav Babuska ◽  
Jana Kolaja Dobra ◽  
Ludek Dluhos ◽  
Jana Dvorakova ◽  
Jana Moztarzadeh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Adhesion ◽  
Surface Properties ◽  
Surface Characterization ◽  
Titanium Surface ◽  
Human Osteoblast ◽  
Nanostructured Titanium ◽  
Angular Pressing ◽  
Optimal Surface

Titanium offers excellent biocompatibility and extraordinary mechanical properties. As a result, it is used as a material for dental implants. Implants infected by peri-implantitis can be cleaned for successful re-osseointegration. Optimal surface properties, such as roughness and wettability, have a significant impact on cell adhesion. The aim of this study was to evaluate the adhesion and proliferation of osteoblasts on the surface of repeatedly cleaned nanostructured titanium samples. Human osteoblast-like cells MG-63 were seeded on nanostructured titanium specimens manufactured from rods produced by the equal channel angular pressing. For surface characterization, roughness and wettability were measured. Cell adhesion after 2 h as well as cell proliferation after 48 h from plating was assessed. We have found that this repeated cleaning of titanium surface reduced cell adhesion as well as proliferation. These events depend on interplay of surface properties, such as wettability, roughness and topography. It is difficult to distinguish which factors are responsible for these events and further investigations will be required. However, even after the several rounds of repeated cleaning, there was a certain rate of adhesion and proliferation recorded. Therefore the attempts to save failing implants by using in situ cleaning are promising.

Effect of Aging Treatment on Mechanical Properties and Electrical Conductivity of Cu-5.7%Cr In Situ Composite Produced by Equal Channel Angular Pressing

2012 ◽  
Vol 560-561 ◽  
pp. 344-348 ◽  
Author(s):  
Wei Wei ◽  
Kun Xia Wei ◽  
Igor V. Alexandrov ◽  
Qing Bo Du ◽  
Jing Hu
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Equal Channel Angular Pressing ◽  
Aging Treatment ◽  
In Situ Composite ◽  
Angular Pressing ◽  
Peak Aging ◽  
Average Size ◽  
Equiaxed Grains

The effect of aging treatment on mechanical properties and electrical conductivity of Cu-5.7%Cr in situ composite produced by equal channel angular pressing (ECAP) was investigated here. The rotation and spreading of Cr particles was observed in Cu-5.7%Cr alloy during the ECAP, resulting in long thin in situ filaments. The equiaxed grains of the Cu phase with an average size of 200 nm were developed after eight passes of ECAP. When aging at 400~450 °C for 1 h, Cu-5.7%Cr composite after ECAP shows the maximum microhardness, and the electrical conductivity is larger than 70% of IACS. At 400 °C, the peak aging time appears for 0.5~2 h, dependent on the pre-strain for all ECAP samples. With the increase of ECAP passes, the enhancement of tensile strength due to the aging treatment declines, and even shows negative after eight passes of ECAP. The combination of ECAP and aging treatment would be a promising process to balance mechanical properties and electrical conductivity of Cu-5.7%Cr composite.

scholarly journals Femtosecond Laser Nano/Micro Textured Ti6Al4V Surfaces—Effect on Wetting and MG-63 Cell Adhesion

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2210 ◽  
Author(s):  
Georg Schnell ◽  
Susanne Staehlke ◽  
Ulrike Duenow ◽  
J. Barbara Nebe ◽  
Hermann Seitz
Keyword(s):  
Cell Adhesion ◽  
Surface Properties ◽  
Laser Scanning ◽  
Surface Characterization ◽  
Cellular Adhesion ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Material Surface ◽  
Structured Surfaces

Nano- and microstructured titanium surfaces have recently attracted attention in the field of regenerative medicine because of the influence which surface characteristics such as roughness and wettability can have on cellular processes. This study focuses on the correlation of surface properties (wettability and nano/micro texture) of laser-structured Ti6Al4V samples with pronounced cell adhesion. Samples were structured with multiple laser parameters in order to create a range of surface properties. Surface characterization was performed by contact angle measurements 1 and 7 days after laser processing. The arithmetic mean roughness of the material surface in an area (Sa) was determined by means of confocal laser scanning microscopy (CLSM). Immediately after wettability tests of the laser-structured surfaces, in vitro experiments with human MG-63 osteoblasts were carried out. For this purpose, the cell morphology and actin cytoskeleton organization were analyzed using CLSM and scanning electron microscopy. On rough microstructures with deep cavities, the cell growth and spreading were inhibited. An improved cellular adhesion and growth on nanostructured and sinusoidal microstructured surfaces could be demonstrated, regardless of hydrophilicity of the surfaces.

scholarly journals The Correlation of Microstructure and Mechanical Properties of In-Situ Al-Mg2Si Cast Composite Processed by Equal Channel Angular Pressing

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1553 ◽  
Author(s):  
Mahdi Chegini ◽  
Mohammad Shaeri ◽  
Reza Taghiabadi ◽  
Sajjad Chegini ◽  
Faramarz Djavanroodi
Keyword(s):  
Mechanical Properties ◽  
Uniform Distribution ◽  
Equal Channel Angular Pressing ◽  
Angular Pressing ◽  
Ecap Process ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Shear Punch ◽  
Average Size

In this paper, the effect of equal channel angular pressing (ECAP) on microstructure and mechanical properties of hypereutectic Al-20%Mg2Si and Al-15%Mg2Si, as well as hypoeutectic Al-10%Mg2Si composites has been investigated. After fabricating the composites by in-situ casting, the composites were processed using the ECAP process up to two passes at room temperature. Microstructural studies have been carried out using a field emission scanning electron microscopy equipped with an energy dispersive X-ray spectrometer. Mechanical properties were also documented using Vickers microhardness and shear punch tests. In the hypereutectic composites, a decrease in the average size of pro-eutectic Mg2Si (Mg2Sip) particles, breakages in eutectic networks, and lengthening of the Al (α) phase in direction of shear bands were observed after the ECAP process. For instance, the average size of Mg2Sip Particles in Al-20%Mg2Si composite reduced from 40 to 17 μm after 2 passes of ECAP. Furthermore, a uniform distribution of Mg2Sip particles was developed in the matrix. In hypoeutectic composite, the ECAP process caused a uniform distribution of eutectic Mg2Si (Mg2SiE) in the matrix that considered a favorable microstructure. Microhardness measurements and shear punch results showed an ascending trend after each pass of ECAP for all specimens. For example, microhardness and shear strength of Al-20%Mg2Si increased from 88 HV and 109 MPa to 119 HV and 249 MPa after two passes indicating 35% and 34% increments, respectively. Density and porosity calculations by Archimedes principle revealed that the density of the composites increased after two passes of ECAP due to the reduction of porosity.

Low Temperature Mechanical Properties of Different Commercial Purity Nanostructured Titanium Processed by ECA Pressing

2006 ◽  
Vol 503-504 ◽  
pp. 633-638 ◽  
Author(s):  
Elena D. Tabachnikova ◽  
Vladimir Z. Bengus ◽  
Aleksey V. Podolskiy ◽  
S.N. Smirnov ◽  
Dmitriy Gunderov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Structural State ◽  
Mechanical Characteristics ◽  
Coarse Grained ◽  
Commercial Purity ◽  
Nanostructured Titanium ◽  
Fine Grained ◽  
Angular Pressing ◽  
Tension And Compression

Low temperature mechanical characteristics under quasistatic uniaxial tension and compression have been studied of ultra fine-grained structural state of polycrystalline titanium – nanostructured titanium, processed by the equal channel angular pressing (ECAP). Values of the yield stress and the uniform plasticity at 300, 77, and 4.2 K for nanostructured (NS) and polycrystalline coarse-grained (CG) titanium of different commercial purity have been compared.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Dynamics of Nanoparticle Chain Aggregates of Carbon Under Tension

2003 ◽  
Vol 778 ◽  
Author(s):  
Rajdip Bandyopadhyaya ◽  
Weizhi Rong ◽  
Yong J. Suh ◽  
Sheldon K. Friedlander
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
Polymer Film ◽  
Elastic Behavior ◽  
Small Strains ◽  
Transmission Electron ◽  
Chain Aggregates ◽  
Nanoparticle Chains ◽  
Reinforcing Filler

AbstractCarbon black in the form of nanoparticle chains is used as a reinforcing filler in elastomers. However, the dynamics of the filler particles under tension and their role in the improvement of the mechanical properties of rubber are not well understood. We have studied experimentally the dynamics of isolated nanoparticle chain aggregates (NCAs) of carbon made by laser ablation, and also that of carbon black embedded in a polymer film. In situ studies of stretching and contraction of such chains in the transmission electron microscope (TEM) were conducted under different maximum values of strain. Stretching causes initially folded NCA to reorganize into a straight, taut configuration. Further stretching leads to either plastic deformation and breakage (at 37.4% strain) or to a partial elastic behavior of the chain at small strains (e.g. 2.3% strain). For all cases the chains were very flexible under tension. Similar reorientation and stretching was observed for carbon black chains embedded in a polymer film. Such flexible and elastic nature of NCAs point towards a possible mechanism of reinforcement of rubber by carbon black fillers.

Sign in / Sign up

Export Citation Format

Share Document