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Prague, Czech Republic

Penttinen N.,University of Eastern Finland | Hason S.,Academy of Sciences of the Czech Republic | Joska L.,Institute of Chemical Technology Prague | Cvrcek L.,HVM Plasma Ltd. | Silvennoinen R.,University of Eastern Finland
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

Chemical components and initial optical responses of Ti 35Nb 6Ta alloy are reported. Polished titanium and other titanium alloy Ti 6Al 4V served as reference surfaces. The chemical composition was determined with an X-ray photoelectron spectroscope (XPS) for the surfaces as well as for water, phosphate buffered saline (PBS) and for human plasma fibrinogen (HPF in PBS) exposed surfaces. The reflectance of the surfaces was modeled utilizing Bruggeman's model, to evaluate the optical changes that the chemical reaction of each liquid can produce. After the model, a diffractive optical element (DOE) based sensor was used to determine the temporal optical signal from the sample surfaces. The coherent and non-coherent signals gathered with DOE sensor were compared to the reflectance model. Exposing to the liquids showed surface oxidation, which could produce lowered reflectance of the surface. The model and the initial temporal responses showed similarities in non-coherent reflectance. © 2011 SPIE.

Franta L.,Czech Technical University | Fojt J.,Institute of Chemical Technology Prague | Joska L.,Institute of Chemical Technology Prague | Kronek J.,Czech Technical University | And 4 more authors.
Tribology International | Year: 2013

The primary goal was to compare model replacements with and without DLC layer. Components were made of the Ti6Al4V alloy and coated with a DLC layer, the sliding sleeve made of a PEEK polymer. Testing was done in the saline physiological solution (9 g/L NaCl). The measuring system was supplemented with the corrosion behavior monitoring. The results show that the applied DLC coating significantly increases the service life of the implant. Based on the results it is possible to state that an accurate mechanical load together with corrosion behavior monitoring shifts testing in the given field to a qualitatively higher level. © 2012 Elsevier Ltd. All rights reserved.

Silvennoinen R.,University of Eastern Finland | Hason S.,Academy of Sciences of the Czech Republic | Vetterl V.,Academy of Sciences of the Czech Republic | Penttinen N.,University of Eastern Finland | And 6 more authors.
Applied Optics | Year: 2010

Adsorption of the elongated human plasma fibrinogen (HPF) and globular human serum albumin molecules on a titanium-based surface is monitored by analyzing permittivity and optical roughness of protein-modified surfaces by using a diffractive optical element (DOE)-based sensor and variable angle spectro-ellipsometry (VASE). Both DOE and VASE confirmed that fibrinogen forms a thicker and more packed surface adlayer compared to a more porous and weakly adsorbed albumin adlayer. A linear relation of the permittivity (ε′)and dielectric loss (ε″)was found for some of the dry titanium-doped hydrocarbon (TDHC) surfaces with excellent HPFadsorption ability.We discuss some aspects of TDHC's aging and its possible effects on fibrinogen adsorption. © 2010 Optical Society of America.

Prachar P.,Fm Mu And St Annes University Hospital Brno | Bartakova S.,Fm Mu And St Annes University Hospital Brno | Brezina V.,Fm Mu And St Annes University Hospital Brno | Cvrcek L.,HVM Plasma Ltd. | Vanek J.,Fm Mu And St Annes University Hospital Brno
Bratislava Medical Journal | Year: 2015

Introduction: The positive cell response to the implant material is reflected by the capacity of cells to divide, which leads to the tissue regeneration and osseointegration. Technically pure titanium and its alloys are mostly used for implant manufacturing. These alloys have the adequate mechanical, physical and biological properties; nevertheless, the superior biocompatibility of bioceramics has been proven. With the arrival of new coating techniques, surface modification of materials used for implants has become a widely investigated issue. Methods: The paper studied properties of titanium nitride (TiN) and zirconium nitride (ZrN) coatings deposited by PVD (Physical Vapour Deposition). Coatings were applied to substrates of pure titanium, Ti6Al4V, Ti35Nb6Ta titanium alloys and CoCrMo dental alloy. Different treatments of substrate surfaces were used: polishing, etching and grit blasting. Cytocompatibility tests assessed the cell colonization and their adherence to substrates. Results and conclusion: Results showed that TiN layers deposited by PVD are suitable for coating all substrates studied. The polished samples and those with TiN coating exhibited a higher cell colonization. This coating technique meets the requirements for the biocompatibility of the implanted materials; furthermore, their colour range solves the issue of red aesthetics in oral implantology as the colour of these coatings prevents titanium from showing through the gingiva. This is one the most important criteria for the aesthetic success of implant therapy (Tab. 5, Ref. 18). Text in PDF www.elis.sk.

Fort T.,Academy of Sciences of the Czech Republic | Vitu T.,Czech Technical University | Novak R.,Czech Technical University | Grossman J.,Academy of Sciences of the Czech Republic | And 2 more authors.
Chemicke Listy | Year: 2011

W-C: H hard composite coatings were studied. The comparison of the wear rate of the coating/substrate system and the bare substrate obtained from dynamic impact test clearly demonstrated that the coating significantly extended the lifetime of the samples even for high loads and high number of loading cycles. The obtained results will support the research and development of new metal-doped a-C:H coatings, which exhibit promising properties for future engineering applications, especially in dynamically loaded contacts.

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