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.

In Vitro and In Vivo Surface Reactivity of Various Calcium Phosphate Coatings Deposited Using Electrostatic Spray Deposition (ESD)

2006 ◽  
Vol 309-311 ◽  
pp. 607-610
Author(s):  
Sander C.G. Leeuwenburgh ◽  
Joop G.C. Wolke ◽  
M.C. Siebers ◽  
J. Schoonman ◽  
John A. Jansen
Keyword(s):  
Calcium Phosphate ◽  
Fibrous Tissue ◽  
Tissue Response ◽  
Specific Chemical ◽  
Phosphate Coatings ◽  
Time Periods ◽  
Tissue Reactions ◽  
Calcium Phosphate Coatings

The dissolution and precipitation behavior of various porous, ESD-derived calcium phosphate coatings was investigated a) in vitro after soaking in Simulated Body Fluid (SBF) for several time periods (2, 4, 8, and 12 weeks), and b) in vivo after subcutaneous implantation in the back of goats for identical time periods. At the end of these studies, the physicochemical properties of the coated substrates were characterized by means of Scanning Electron Microscopy (SEM), XRay Diffraction (XRD), Fourier-Transform InfraRed spectroscopy (FTIR) and Energy Dispersive Spectroscopy (EDS). Moreover, part of the implants was prepared for light microscopical evaluation of the tissue response. In vitro, a highly bioactive behavior was observed for all ESD-coatings, characterized by the deposition of a thick and homogeneous carbonate hydroxyapatite precipitation layer on top of the porous coatings. Regarding the in vivo study, no adverse tissue reactions (toxic effects/inflammatory cells) were observed using light microscopy, and all coatings became surrounded by a thin, dense fibrous tissue capsule after implantation. The ESD-coatings degraded gradually at a dissolution rate depending on the specific chemical phase, thereby enabling synthesis of CaP coatings with a tailored degradation rate.

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.

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.

Osseointegration of Calcium Phosphate Nanofilms on Titanium Alloy Implants

2007 ◽  
Vol 361-363 ◽  
pp. 645-648
Author(s):  
M.D. Paz ◽  
Stefano Chiussi ◽  
Pio González ◽  
Julia Serra ◽  
Betty León ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Titanium Alloy ◽  
Calcium Phosphate ◽  
Bone Regeneration ◽  
Bone Growth ◽  
Pulsed Laser ◽  
Titanium Implants ◽  
Optical Methods ◽  
Phosphate Coatings ◽  
Calcium Phosphate Coatings

In the present work two different hydroxyapatite nanofilms (50 and 100 nm thick) have been successfully deposited on titanium implants that were previously laser macrostructured in order to assess the influence of the thickness of nanometric calcium phosphate coatings on the osseointegration. Cylindrical implants were tested in a sheep tibia model together with titanium alloy controls achieving very good osseointegration results. Laser macrostructured titanium alloy implants have shown improved bone regeneration when coated with nanometric films of carbonated HA. The pulsed laser deposited nanofilm has promoted bone in-growth deep into the laser ablated craters. There were no significant differences between the two coating thicknesses, neither when assessed with electron microscopy or classical optical methods. This result suggests that the 50 nm coating is as effective as the 100 nm one, therefore implying that the thickness limit for such a bioactive layer to stimulate bone growth may be even further below.

In vivo Osteogenerating Properties of Calcium Phosphate Coatings on Ti-6Al-4V Titanium Alloy

2017 ◽  
Vol 51 (2) ◽  
pp. 116-119 ◽  
Author(s):  
S. V. Gnedenkov ◽  
S. L. Sinebryukhov ◽  
A. V. Puz’ ◽  
R. E. Kostiv
Keyword(s):  
Titanium Alloy ◽  
Calcium Phosphate ◽  
Phosphate Coatings ◽  
Calcium Phosphate Coatings
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