Effect of ZrO2 on Mechanical and Biological Properties of Calcium Phosphate-Based Glass-Ceramics for Biomedical Applications

2008 ◽  
Vol 368-372 ◽  
pp. 1429-1432 ◽  
Author(s):  
Cai Yun Zheng ◽  
Shu Jun Li ◽  
Yu Lin Hao ◽  
Rui Yang

The effect of ZrO2 addition on mechanical and biological properties of bioactive glass-ceramics with chemical compositions of 60CaO-30P2O5-3TiO2-xZrO2-(7-x)Na2O (x=0,1,3) was investigated. It was found that ZrO2 addition up to 3 mol% contributes to monotonical increase of the glass transition temperature. The micro-hardness increases slightly by 1 mol% ZrO2 addition and keeps constant with further addition whereas 1 mol% ZrO2 addition results in ~20% increase of three-point bending strength. When the specimens were soaked in simulated body fluid, complete apatite layers were formed on the specimens regardless of the ZrO2 addition. It is therefore concluded that the toughening contribution of 1 mol% ZrO2 addition has no adverse effect on the bioactivity of calcium phosphate glass-ceramics.

2017 ◽  
Vol 8 ◽  
pp. 204173141771917 ◽  
Author(s):  
Md Towhidul Islam ◽  
Reda M Felfel ◽  
Ensanya A Abou Neel ◽  
David M Grant ◽  
Ifty Ahmed ◽  
...  

An overview of the formation of calcium phosphate under in vitro environment on the surface of a range of bioactive materials (e.g. from silicate, borate, and phosphate glasses, glass-ceramics, bioceramics to metals) based on recent literature is presented in this review. The mechanism of bone-like calcium phosphate (i.e. hydroxyapatite) formation and the test protocols that are either already in use or currently being investigated for the evaluation of the bioactivity of biomaterials are discussed. This review also highlights the effect of chemical composition and surface charge of materials, types of medium (e.g. simulated body fluid, phosphate-buffered saline and cell culture medium) and test parameters on their bioactivity performance. Finally, a brief summary of the biomedical applications of these newly formed calcium phosphate (either in the form of amorphous or apatite) is presented.


2001 ◽  
Vol 16 (3) ◽  
pp. 876-880 ◽  
Author(s):  
Toshihiro Kasuga ◽  
Miwako Terada ◽  
Masayuki Nogami ◽  
Mitsuo Niinomi

Glass-ceramics containing a large amount of calcium pyrophosphate (β–Ca2P2O7) crystal were prepared via crystallization and sintering; compacts of a calcium phosphate glass powders with a composition of 60CaO · 30P2O5 · 5TiO2 · 5Na2O (in mol%) were heated for 3–6 h at 850 °C in air. The compacts were densified by the viscous flow of the glassy phases during heating. The calcium phosphate glass-ceramics were found to show a bending strength of approximately 100 MPa, and they were easy to machine, as confirmed by a drilling test using a conventional carbide tool. The machinability is thought to arise from the microstructure consisting predominantly of the interlocking and platelike β–Ca2P2O7 precipitated in the glass.


2020 ◽  
Vol 16 (5) ◽  
pp. 779-792
Author(s):  
Ahlam M. Fathi ◽  
Howida S. Mandour ◽  
Hanaa K. Abd El-Hamid

Background: Increasing the bioactivity of metallic implants is necessary for biomaterial applications where hydroxyapatite (HA) is used as a surface coating. In industry, HA is currently coated by plasma spraying, but this technique has a high cost and produces coating with short-term stability. Objectives: In the present study, electrophoretic deposition (EPD) was used to deposit nano-biphasic calcium phosphate compound (β-tri-calcium phosphate (β-TCP) /hydroxyapatite (HA)) bio-ceramics on the titanium surface. The microstructural, chemical compositions and bioactivity of the β- TCP/HA coatings were studied in a simulated body fluid solution (SBF). Methods: Scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR) were used. Additionally, the antibacterial effect was studied by the agar diffusion method. The corrosion behavior of the β-TCP/HA coating on titanium surface (Ti) in the SBF solution at 37oC was investigated by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests. Results: The Ti surface modification increased its biocompatibility and corrosion resistance in the simulated body fluid. The antibacterial inhibition activity of the β-TCP/HA bio-ceramic was enhanced by electroless silver deposition. The enhanced properties could be attributed to the use of nano-sized biphasic calcium phosphates in a low-temperature EPD process. Conclusions: The β-TCP/HA and β-TCP/HA/Ag coatings well protect Ti from the corrosion in SBF and endow Ti with biocompatibility. The β-4-TCP/HA/Ag/Ti substrate shows good antibacterial activity.


2011 ◽  
Vol 84-85 ◽  
pp. 58-63
Author(s):  
Zi Li Liu ◽  
Fei Fei ◽  
Ping Shen ◽  
Gui Bin Zhou ◽  
Xi Qin Liu

Mg-xZr damping alloys (x=0.6, 1.5, 2.5, 5, mass %) were prepared by PM (powder metallurgy ) technology, and effects of Zr contents on microstructure, mechanical properties and damping capacities of Mg-xZr damping alloys were researched by three-point bending test and DMA, etc. The results show that the microstructure become into strip-shaped morphology, more granular particles appear in the grain boundaries or inside grains, and the grains are more refined with the increase of Zr additions. Micro-hardness and bending strength of the Mg-xZr damping alloys increase with increasing addition of Zr, and reach the maximum value with Zr addition of 2.5%. The damping capacities of Mg-xZr alloys increase slowly with the temperature from 27°C to 100°C, and increase rapidly above 100°C. The damping peaks appear at temperature of 160°C. Mg-5%Zr alloy exhibits the highest damping capacity, and its tanf value reaches to 0.084. The temperature of the damping peak increases with increasing frequencies, showing the characteristic of relaxation damping.


2013 ◽  
Vol 334-335 ◽  
pp. 297-302 ◽  
Author(s):  
A.L.A. Escada ◽  
João Paulo Barros Machado ◽  
Roberto Zenhei Nakazato ◽  
Ana Paula Rosifini Alves Claro

Titanium and its alloys are widely used as biomaterials due to their mechanical, chemical and biological properties. To enhance the biocompatibility of titanium alloys, various surface treatments have been proposed. In particular, the formation of titanium oxide nanotubes layers has been extensively examined. Among the various materials for implants, calcium phosphates and hydroxyapatite are widely used clinically. In this work, titanium nanotubes were fabricated on the surface of Ti-7.5Mo alloy by anodization. The samples were anodized for 20 V in an electrolyte containing glycerol in combination with ammonium fluoride (NH4F, 0.25%), and the anodization time was 24 h. After being anodized, specimens were heat treated at 450 °C and 600°C for 1 h to crystallize the amorphous TiO2 nanotubes and then treated with NaOH solution to make them bioactive, to induce growth of calcium phosphate in a simulated body fluid. Surface morphology and coating chemistry were obtained respectively using, field-emission scanning electron microscopy (FEG-SEM), AFM and X-ray diffraction (XRD). It was shown that the presence of titanium nanotubes induces the growth of a sodium titanate nanolayer. During the subsequent in-vitro immersion in a simulated body fluid, the sodium titanate nanolayer induced the nucleation and growth of nanodimensioned calcium phosphate. It was possible to observe the formation of TiO2 nanotubes on the surface of Ti-7.5Mo. Calcium phosphate coating was greater in the samples with larger nanotube diameter. These findings represent a simple surface treatment for Ti-7.5Mo alloy that has high potential for biomedical applications.


2011 ◽  
Vol 287-290 ◽  
pp. 642-649
Author(s):  
Zi Li Liu ◽  
Gui Bin Zhou ◽  
Ping Shen ◽  
Xi Qin Liu ◽  
Huai Tao Wang

Mg-1.5%Zr-x%Cd alloys (x=0, 0.5, 1.0, 1.5, mass%) were prepared by PM (powder metallurgy) technology, and the microstructure, mechanical properties and damping capacities of the alloys were researched by OM, three-point bending test and DMA, etc. The results show that the microstructure becomes into strip or block shaped morphology, granular particles Zr appear at grain boundaries or inside grains, and the grains are more refined with the increase of Cd additions. Micro-hardness(HV) and bending strength(σbb) of the alloys increase with increasing addition of Cd. Damping capacities of the Mg-1.5%Zr-x%Cd alloys improves with Cd additions, and increase with the temperature. The damping peak temperature increases with increasing frequencies, showing the characteristic of relaxation damping.


2006 ◽  
Vol 309-311 ◽  
pp. 1185-1190 ◽  
Author(s):  
Xu Dong Li ◽  
Xiao Min Wang ◽  
Xiao Yan Lin ◽  
Jian Ming Jiang ◽  
Xing Dong Zhang

An organic/inorganic composite hydrogel route was used to prepare collagen-calcium phosphate hybrids with high mechanical strengths, via in-situ mineral synthesis during collagen fibrillogenesis followed by dehydration. An array of characterization techniques including X-ray diffraction and Fourier transform infrared spectroscopy analyses confirmed that the final products are analogous to natural bone. A three-point bending strength of 70 MPa, much higher than the values reported in the literature, was recorded in the present case, due to the three dimensional network structure achieved between inorganic and organic phases. This innovative method provides an efficient route to produce bone grafts with the desirable mechanical properties which are dependent upon the actual inorganic/organic ratio and water content.


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