Injectability of a Macroporous Calcium Phosphate Cement

2005 ◽  
Vol 284-286 ◽  
pp. 157-160 ◽  
Author(s):  
J.A. Delgado ◽  
I. Harr ◽  
Amisel Almirall ◽  
Sergio del Valle ◽  
Josep A. Planell ◽  
...  
Keyword(s):  
Particle Size ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Tricalcium Phosphate ◽  
Extrusion Process ◽  
X Ray Diffraction ◽  
Foaming Agent ◽  
X Ray ◽  
Ir Analysis ◽  
Hydrolysis Of

In this work an injectable and self setting calcium phosphate/albumen foam is developed. The effect of both the amount of albumen and the particle size of the starting a-tricalcium phosphate (a-TCP) powder on the injectability of the cement paste is studied. X-ray diffraction (XRD) and infrared (IR) analysis of the samples reveal that the hydrolysis of a-TCP to calcium deficient hydroxyapatite (CDHA) is not affected by the addition of albumen. A foamed structure formed by spherical pores with diameters between 100 and 500 µm is observed by SEM. This porous structure is maintained after injection of the paste, although some deformation of the pores is produced due to the extrusion process. The injectability of the cements is increased by the presence of albumen as compared with cements prepared in the same conditions but without foaming agent.

Fabrication and evaluation of calcium phosphate cement scaffold with controlled internal channel architecture and complex shape

2007 ◽  
Vol 221 (8) ◽  
pp. 951-958 ◽  
Author(s):  
X Li ◽  
D Li ◽  
B Lu ◽  
L Wang ◽  
Z Wang
Keyword(s):  
Tissue Engineering ◽  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
Complex Shape ◽  
X Ray Diffraction ◽  
X Ray ◽  
Precise Control ◽  
Internal Channel ◽  
Channel Architecture

The ability to have precise control over internal channel architecture, porosity, and external shape is essential for tissue engineering. The feasibility of using indirect stereo-lithography (SL) to produce scaffolds from calcium phosphate cement materials for bone tissue engineering has been investigated. The internal channel architecture of the scaffolds was created by removal of the negative resin moulds made with SL. Scanning electron microscopy (SEM) showed highly open, well-interconnected channel architecture. The X-ray diffraction examination revealed that the hydroxyapatite phase formed at room temperature in the cement was basically stable up to 850 °C. There was no phase decomposition of hydroxyapatite, although the crystallinity and grain size were different. The ability of resulting structure to support osteoblastic cells culture was tested in vitro. Cells were evenly distributed on exterior surfaces and grew into the internal channels of scaffolds. To exploit the ability of this technique, anatomically shaped femoral supracondylar scaffolds with 300-800 μm interconnected channels were produced and characterized.

Synthesis of Alpha-Tricalcium Phosphate by Wet Reaction and Evaluation of Mechanical Properties

2012 ◽  
Vol 727-728 ◽  
pp. 1164-1169 ◽  
Author(s):  
Mônica Beatriz Thürmer ◽  
Rafaela Silveira Vieira ◽  
Juliana Machado Fernandes ◽  
Wilbur Trajano Guerin Coelho ◽  
Luis Alberto Santos
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Phosphate Cements

Calcium phosphate cements have bioactivity and osteoconductivity and can be molded and replace portions of bone tissue. The aim of this work was to study the obtainment of α-tricalcium phosphate, the main phase of calcium phosphate cement, by wet reaction from calcium nitrate and phosphoric acid. There are no reports about α-tricalcium phosphate obtained by this method. Two routes of chemical precipitation were evaluated and the use of two calcinations temperatures to obtain the phase of cement. The influence of calcination temperature on the mechanical properties of cement was evaluated. Cement samples were characterized by particle size analysis, X-ray diffraction, mechanical strength and scanning electron microscopy. The results demonstrate the strong influence of synthesis route on the crystalline phases of cement and the influence of concentration of reactants on the product of the reaction, as well as, on the mechanical properties of cement.

Enhancing the Bonding Strength of Plasma-Sprayed HA Coating on Pure Ti

2007 ◽  
Vol 561-565 ◽  
pp. 1553-1556 ◽  
Author(s):  
Sen Yang ◽  
Hau Chung Man
Keyword(s):  
Calcium Phosphate ◽  
Calcium Oxide ◽  
Tricalcium Phosphate ◽  
X Ray Diffraction ◽  
Tetracalcium Phosphate ◽  
X Ray ◽  
Gas Nitriding ◽  
Ha Coating ◽  
Scaffold Structure ◽  
Plasma Sprayed

A layer of bioceramic HA was coated on laser gas nitrided and grit-blasted pure Ti substrates using plasma-spraying technique, respectively. X-ray diffraction analysis showed that the microstructures of the coating were mainly composed of HA, amorphous calcium phosphate and some minute phases of tricalcium phosphate, tetracalcium phosphate and calcium oxide. The experimental results showed that the 3-D TiN dendritic scaffold structure produced on the surface of pure Ti using laser gas nitriding technique in advance could anchor the HA coating and improved the interfacial adherence significantly as compared with those on the grit blasted surfaces.

Studies on Non-Quenched Calcium Phosphate Cement: Influences of Quenching and Milling on Setting Characteristic

2007 ◽  
Vol 330-332 ◽  
pp. 39-42 ◽  
Author(s):  
Xue Jiang Wang ◽  
Yu Bao Li ◽  
John A. Jansen ◽  
Shi Hong Li ◽  
Joop G.C. Wolke
Keyword(s):  
Particle Size ◽  
Calcium Phosphate ◽  
Surface Area ◽  
Calcium Phosphate Cement ◽  
Tricalcium Phosphate ◽  
Hydrated Layer ◽  
Initial Setting

The aim of this study is to explore the effects of quenching and milling processing on setting property of calcium phosphate cement (CPC). For this purpose, non-quenched α-tricalcium phosphate (α-TCP) and quenched α-TCP were synthesized and their corresponding cement systems were prepared. The particle size of α-TCP powder was introduced as a variable. Then, setting properties of these CPC systems were estimated. By a comparison between non-quenched CPC and the quenched one, it is found that milling processing mainly influences the initial setting stage by decreasing reactant particle size whereas the quenching treatment affects the final setting stage by changing α-TCP content, which supports that CPC setting initially depends on the surface area of reactants and subsequently on the diffusion through the hydrated layer formed around the reactants.

Synthesis of Chicken’s Eggshells-Based β-Tricalcium Phosphate Bioceramics

2015 ◽  
Vol 1112 ◽  
pp. 458-461
Author(s):  
Kiagus Dahlan ◽  
Nur Aisyah Nuzulia
Keyword(s):  
Fourier Transform ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
X Ray ◽  
Dental Application ◽  
Good Biocompatibility ◽  
Ca:P Ratio

The use of bioceramics for orthopedic and dental application nowadays increases due to their good biocompatibility and osteoconductivity. β-tricalcium phosphate (β-TCP) bioceramics which have excellent biodegradation properties have been in use quite extensively. This paper reports the synthesis of β-TCP bioceramics from precipitation of calcined chicken’s eggshells and phosphoric acid (H3PO4). Chicken’s eggshells were calcined at 1000°C for 5 hours to form calcium oxide (CaO). Various molarities of CaO and H3PO4, between 0.4 M and 2.4 M, were used in this experiment with the Ca:P ratio was kept 1.5:1. After precipitation, the samples were filtered and heated at a sintering temperature of 1000°C for 7 hours. The X Ray Diffraction profile showed that the patterns were affected by the molarity. The patterns of 1.2 M CaO/0.8 M H3PO4 samples showed pure β-TCP, while those of 0.6 M CaO/0.4 M H3PO4 and 2.4 M CaO/1.6 M H3PO4 samples showed the presence of hydroxyapatite and octa calcium phosphate. These findings were also supported by Fourier transform infrared spectra. The purity of the samples shown by the atomic absorption spectroscopy resulted in Ca:P ratio of 1.48:1 which is very closed to that of standard β-TCP bioceramics.

Preparation and Properties of Calcium Phosphate Cement Containing ZnO Whisker

2009 ◽  
Vol 610-613 ◽  
pp. 1044-1048
Author(s):  
Ya Meng Guo ◽  
Dong Xu Li ◽  
Yan Bao Li
Keyword(s):  
Calcium Phosphate ◽  
Calcium Phosphate Cement ◽  
X Ray Diffraction ◽  
Hardening Material ◽  
X Ray ◽  
Crystal Fiber ◽  
Key Factor ◽  
New Type ◽  
Bone Repairing ◽  
Scanning Electron

Calcium phosphate cement (CPC) is a self-hardening material for bone repairing. ZnO whisker is a new type reinforced materials lately, which is acerose single crystal fiber. In this study, ZnO whisker was added into the CPC with different ratios, and each specimen kept at 37 oC in 100% humidity for 24 hrs. The phase and microstructure of the calcium phosphate pastes were investigated using X-ray diffraction and scanning electron microscopy, respectively. It has been found that ZnO whisker could supply nucleating center, TTCP and DCPA could be much easier to form HA around the ZnO whisker. The adding amount of ZnO whisker is a key factor that determines the mechanical properties.

The Preparation and Morphology of Biphasic Calcium Phosphate Ceramics

2012 ◽  
Vol 506 ◽  
pp. 198-201
Author(s):  
P. Saiwanich ◽  
Kamonpan Pengpat ◽  
G. Rujijanagul ◽  
U. Intatha ◽  
Sukum Eitssayeam
Keyword(s):  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
X Ray Diffraction ◽  
Casting Method ◽  
X Ray ◽  
Gel Casting ◽  
Beta Tricalcium Phosphate ◽  
Ceramic Microstructure ◽  
Ball Milling Technique

In this work, thepreparation and morphology of biphasic calcium phosphate (BCP) have been studied. The biphasic calcium phosphate (BCP) ceramics were prepared by mixing between hydroxyapatite (HA) and Beta-tricalcium phosphate (β-TCP) powderby ball milling technique with different ratios (100:0,80:20,60:40,50:50,40:60, 20:80 and 0:100). After that the mixtures were forming by Gel casting method and then sintered at 1200°C, respectively. The phase formation of the biphasic calcium phosphateceramics were studied by X-ray diffraction (XRD) and their ceramic microstructure,shrinkage and density were investigated.

Effect on Mechanical Strength of Tricalcium Phosphate Cement by Additions of Sodium Alginate

2012 ◽  
Vol 727-728 ◽  
pp. 1181-1186 ◽  
Author(s):  
W.T. Coelho ◽  
Juliana Machado Fernandes ◽  
Rafaela Silveira Vieira ◽  
Mônica Beatriz Thürmer ◽  
Luis Alberto Santos
Keyword(s):  
Aqueous Solution ◽  
Compressive Strength ◽  
Calcium Phosphate ◽  
Mechanical Strength ◽  
Sodium Alginate ◽  
Calcium Phosphate Cement ◽  
Bone Substitutes ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
X Ray

The Calcium Phosphate Cement (CPC) are bone substitutes with great potential for use in orthopedics, traumatology and dentistry due to its biocompatibility, bioactivity and osteoconductivity, and form a paste that can be easily shaped and placed into the surgical site. However, CPCs have low mechanical strength, which equals the maximum mechanical strength of trabecular bone. In order to assess the strength and time to handle a CPC composed primarily of alpha phase, were added sodium alginate (1%, 2% and 3% wt) and an accelerator in an aqueous solution. The cement powder was mixed with liquid of setting, shaped into specimens and evaluated for apparent density and porosity by Archimedes method, X-ray diffraction and compressive strength. A significant increase in compressive strength by adding sodium alginate was verified.

Identification of acid-insoluble filter-plugging compounds and optimal acid-washing procedures for tubular backpulse pressure filters

TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER
Keyword(s):  
Calcium Sulfate ◽  
Membrane Filter ◽  
Sulfamic Acid ◽  
Xrd Analysis ◽  
Metal Sulfides ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gypsum Formation ◽  
Acid Washing ◽  
Hydrolysis Of

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.

Investigation of the products of carbothermal reduction of yttrium oxide by the hydrolysis method

1984 ◽  
Vol 49 (4) ◽  
pp. 936-943 ◽  
Author(s):  
Bohumil Hájek ◽  
Pavel Karen ◽  
Vlastimil Brožek
Keyword(s):  
Yttrium Oxide ◽  
Carbothermal Reduction ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrolysis Method ◽  
Sample Decomposition ◽  
Products Of Reaction ◽  
Hydrolysis Of ◽  
Lower Carbon

For the investigation of the products of reaction of yttrium oxide with carbon mixed in various proportions, the chemical and X-ray diffraction methods of analysis were combined with the gas chromatographic analysis of the mixture of hydrocarbons and hydrogen formed on the sample decomposition with water. The carboreduction of Y2O3 was examined at relatively low temperatures, convenient for obtaining the reaction intermediates in higher yields. At 1 600 °C and pressures of 10-3 Pa the reduction of a mixture of Y2O3 with carbon in a stoichiometric ratio of 1 : 7 yields YC2 in equilibrium with 20% of Y2OC phase. At lower carbon contents (down to the Y2O3 : C ratio of 1 : 2) tha fraction of the Y2OC phase increases up to approximately 30%. In addition to Y2O3, the reaction mixture contains also Y2C, Y2OC and a phase giving propyne on hydrolysis. The presence of traces of C3 hydrocarbons and small amounts of methane in the product of hydrolysis of the carbide sample prepared by the carbothermal reduction of the oxide can be explained in terms of the occurrence of the Y15C19 phase, probably substituted in part by oxygen, and of the Y2OC phase. The results are compared with those obtained previously for the Sc2O3 + C system.

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