scholarly journals Nanotubular Oxide Layers and Hydroxyapatite Coatings on Porous Titanium Alloy Ti13Nb13Zr

2018 ◽  
Vol 18 (4) ◽  
pp. 17-23 ◽  
Author(s):  
M. Supernak-Marczewska ◽  
A. Ossowska ◽  
P. Strąkowska ◽  
A. Zieliński
Keyword(s):  
Titanium Alloy ◽  
Surface Condition ◽  
Porous Titanium ◽  
Biological Processes ◽  
Porous Substrate ◽  
Oxide Layers ◽  
Physical Chemical ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
Calcium Phosphate Coatings

AbstractThe surface condition of an implant has a significant impact on response occurring at the implant-biosystem border. The knowledge of physical-chemical and biological processes allows for targeted modification of biomaterials to induce a specified response of a tissue. The present research was aimed at development of technology composing of obtaining the nanotube oxide layers on a porous titanium alloy Ti13Nb13Zr, followed by the deposition of phosphate coating. The porous substrate (porosity about 50%) was prepared by a selective laser melting of the Ti13Nb13Zr powder with the SLM Realizer 100 equipment. The nanotubular oxide layers were fabricated by electrochemical oxidation in H3PO4 + 0.3% HF mixture for 30 min. at a constant voltage of 20V. The calcium phosphate coatings were formed by the electrochemically assisted deposition (ECAD). The presence of nanotubular oxide layers with their internal diameters ranging from 30 to 100 nm was observed by SEM (JEOL JSM-7600F). The nanotubes have dimensions that facilitated the deposition of hydroxyapatite.

scholarly journals Formation of Solution-derived Hydroxyapatite Coatings on Titanium Alloy in the Presence of Magnetron-sputtered Alumina Bond Coats

2015 ◽  
Vol 9 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Anna Zykova ◽  
Vladimir Safonov ◽  
Anna Yanovska ◽  
Leonid Sukhodub ◽  
Renata Rogovskaya ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Calcium Phosphate ◽  
Ceramic Materials ◽  
Tissue Response ◽  
Hybrid Technique ◽  
Bond Coats ◽  
Ceramic Oxide ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
Calcium Phosphate Coatings

Hydroxyapatite Ca10(PO4)6(OH)2(HAp) and calcium phosphate ceramic materials and coatings are widely used in medicine and dentistry because of their ability to enhance the tissue response to implant surfaces and promote bone ingrowth and osseoconduction processes. The deposition conditions have a great influence on the structure and biofunctionality of calcium phosphate coatings. Corrosion processes and poor adhesion to substrate material reduce the lifetime of implants with calcium phosphate coatings. The research has focused on the development of advanced methods to deposit double-layered ceramic oxide/calcium phosphate coatings by a hybrid technique of magnetron sputtering and thermal methods. The thermal method can promote the crystallization and the formation of HAp coatings on titanium alloy Ti6Al4V substrates at low temperature, based on the principle that the solubility of HAp in aqueous solutions decreases with increasing substrate temperature. By this method, hydroxyapatite directly coated the substrate without precipitation in the initial solution. Using a thermal substrate method, calcium phosphate coatings were prepared at substrate temperatures of 100-105oC. The coated metallic implant surfaces with ceramic bond coats and calcium phosphate layers combine the excellent mechanical properties of metals with the chemical stability of ceramic materials. The corrosion test results show that the ceramic oxide (alumina) coatings and the double-layered alumina-calcium phosphate coatings improve the corrosion resistance compared with uncoated Ti6Al4V and single-layered Ti6Al4V/calcium phosphate substrates. In addition, the double-layered alumina/hydroxyapatite coatings demonstrate the best biocompatibility duringin vitrotests.

Biphasic and Preferentially Oriented Microcrystalline Calcium Phosphate Coatings: In Vitro and In Vivo Studies

2005 ◽  
Vol 284-286 ◽  
pp. 207-210 ◽  
Author(s):  
Hyun Bin Kim ◽  
Yogesh K. Vohra ◽  
Patrick J. Louis ◽  
William R. Lacefield ◽  
Jack E. Lemons ◽  
...  
Keyword(s):  
In Vivo Studies ◽  
In Vitro Dissolution ◽  
Thin Film Coatings ◽  
In Vivo Experiments ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
Surgical Extraction ◽  
Calcium Phosphate Coatings

We report results of in-vitro and in-vivo studies on biphasic thin film coatings of hydroxyapatite/tetracalcium phosphate produced by pulsed laser deposition using ablation targets of crystalline hydroxyapatite. Changes in coating phase composition during in-vitro dissolution experiments were monitored by x-ray diffraction. Scanning electron microscopy was used to assess variations in surface morphology. In-vivo experiments involving the insertion of coated metallic implants in the proximal tibia and distal femur of New Zealand White Rabbits were carried out. Histomorphometric studies on implant samples after surgical extraction show that biphasic coatings produced may lead to enhanced osteointegration compared to pure hydroxyapatite coatings.

scholarly journals The influence of physical, chemical and biological manipulations on surface potential of calcium phosphate coatings on metal substrates

2011 ◽  
Vol 10 (3) ◽  
pp. 72-81 ◽  
Author(s):  
I. A. Khlusov ◽  
V. F. Pichugin ◽  
E. A. Gostischev ◽  
Yu. P. Sharkeyev ◽  
R. A. Surmenev ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Electrostatic Potential ◽  
Bone Marrow Cells ◽  
Physical Chemical ◽  
Phosphate Coatings ◽  
Roughness Index ◽  
Artificial Surface ◽  
Calcium Phosphate Coatings ◽  
Surface Electrostatic Potential ◽  
Statistical Deviation

The electret voltage indices of artificial surfaces are dependent on coatings formation technology and may be regulated by means of change in their physical-chemical parameters. Chemical modification of radio frequency magnetron calcium phosphate coatings (RFMCPC) by means of silicious incorporation led to an augmentation of pieces’ electrostatic potential. A complication of RFMCPC relief that was fixed by roughness index Ra is accompanied by increase in electret voltage index of artificial surface and its statistical deviation. Bone marrow cells suspension in model biological electrolyte populated RFMCPC dimples. In this manner it modulated the amplitude and leveled out the differences of surface electrostatic potential.

Ca/P Ratio and Biocompatibility of Hydroxyapatite Coatings

1998 ◽  
Author(s):  
P. Frayssinet ◽  
F. Tourenne ◽  
N. Rouquet ◽  
I. Primout ◽  
D. Mathon
Keyword(s):  
Calcium Phosphate ◽  
Coating Thickness ◽  
Small Difference ◽  
Calcium Phosphate Coating ◽  
Phosphate Coating ◽  
Rapid Degradation ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
The Mean ◽  
Calcium Phosphate Coatings

Abstract The decomposition of HA during plasma-spraying can lead to the appearance of calcium oxide (CaO) in the calcium phosphate coatings and an increase of the Ca/P ratio (> 1.67). Rehydration can cause an increase in the pH of the extracellular fluids in close vicinity to the coating and rapid degradation of its thickness. Metal cylinders coated with HA were implanted in rabbit condyles for two months and analyzed by histology to evaluate the effect of the presence of CaO in the coatings during early implantation. Three groups of coatings containing different amounts of CaO: 0.2, 0.5, and 0.9% were implanted . The mean coating thickness was measured on five different sites randomly chosen on each section. The percentage of the coating perimeter in contact with newly farmed bone tissue was also measured. A very small difference in coating thickness was observed between the 0.5% group and the two others. The percentage of coating perimeter in contact with the bone increased with the CaO content. These results show that CaO contamination of the calcium phosphate coating does not impair integration and does not increase degradation during the early stages of implantation.

scholarly journals Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

1999 ◽  
Vol 14 (12) ◽  
pp. 4715-4719 ◽  
Author(s):  
J. M. Fernández-Pradas ◽  
L. Clèries ◽  
G. Sardin ◽  
J. L. Morenza
Keyword(s):  
Pulsed Laser Deposition ◽  
Photoelectron Spectroscopy ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Deposition Rates ◽  
Local Conditions ◽  
X Ray ◽  
Hydroxyapatite Coatings ◽  
Phosphate Coatings ◽  
Calcium Phosphate Coatings

Calcium phosphate coatings, obtained at different deposition rates by pulsed laser deposition with a Nd:YAG laser beam of 355 nm wavelength, were studied. The deposition rate was changed from 0.043 to 1.16 Å/shot by modification of only the ablated area, maintaining the local fluence constant to perform the ablation process in similar local conditions. Characterization of the coatings was performed by scanning electron microscopy, x-ray diffractometry, and infrared, micro-Raman, and x-ray photoelectron spectroscopy. The coatings showed a compact surface morphology formed by glassy grains with some droplets on them. Only hydroxyapatite (HA) and alpha-tricalcium phosphate (α–TCP) peaks were found in the x-ray diffractograms. The relative content of (α–TCP diminished with decreasing deposition rates, and only HA peaks were found for the lowest rate. The origin of (α–TCP is discussed.

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