scholarly journals Concentration Effect of Aqueous Synthesis on Biphasic Hydroxyapatite – β-Tricalcium Phosphate Composition

2010 ◽  
Vol 93-94 ◽  
pp. 405-408 ◽  
Author(s):  
A.S.F. Alqap ◽  
Iis Sopyan ◽  
S.A. Zubir
Keyword(s):  
Phase Composition ◽  
Calcium Phosphate ◽  
Ceramic Material ◽  
Calcium Oxide ◽  
Tricalcium Phosphate ◽  
Biomedical Application ◽  
Functional Material ◽  
Aqueous Synthesis ◽  
Suspension Concentration ◽  
Calcium And Phosphorus

Hydroxyapatite of calcium phosphate materials, one of the most frequently used ceramic material in biomedical application, has been produced via chemical reaction involves both calcium and phosphorus precursors. Effect of suspension concentration on available phases was investigated using a basis of 2 mole % excess of calcium oxide. The synthesis was performed at 90°C until paste was obtained. To improve crystallinity, hydroxyapatite was calcined at 900°C. However, β-TCP appeared as trace which varied in fraction with suspension concentration. Varying concentration is then one approaching method in designing phase composition through which a functional material could be attained.

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.

Effect of Macrophage on Degradation of β-TCP Ceramics

2005 ◽  
Vol 288-289 ◽  
pp. 549-552
Author(s):  
Shi Pu Li ◽  
Hong Lian Dai ◽  
Yu Hua Yan ◽  
Xian Ying Cao ◽  
Qi Xin Zheng
Keyword(s):  
Calcium Phosphate ◽  
Carbonic Anhydrase ◽  
Tricalcium Phosphate ◽  
Culture Medium ◽  
Calcium Phosphate Ceramics ◽  
Sem Observation ◽  
Ph Values ◽  
Calcium And Phosphorus

Mice macrophages which were mixed with β-tricalcium phosphate (β-TCP) ceramics powder were cultured, both calcium and phosphorus concentrations in the culture medium were evidently higher than that of β-TCP ceramics powder without cells. The microscope and SEM observation showed that macrophages wrapped β-TCP particles, and then phagocytized them into cytoplasm. The pH values inside and outside macrophage in β-TCP-bearing were tested. The histochemistry observation showed that there were many carbonic anhydrase positive grains in the cytochylema of macroghage after β-TCP ceramics powder being implanted. TEM investigation indicated that many β-TCP particles were phagocytized into the cytochylema of macroghage, and then vacuole was found after particles had degraded. The results showed that macrophages could take part in the degradation of calcium phosphate ceramics in two different ways.

Synthesis of Amorphous Calcium Phosphate as a Starting Material for α-Tricalcium Phosphate

2017 ◽  
Vol 267 ◽  
pp. 119-123
Author(s):  
Zilgma Irbe ◽  
Armands Buss ◽  
Dagnija Loca ◽  
Lasma Malniece
Keyword(s):  
Calcium Phosphate ◽  
Sodium Hydroxide ◽  
Tricalcium Phosphate ◽  
Amorphous Calcium Phosphate ◽  
Ion Concentration ◽  
Bone Tissue Regeneration ◽  
Content Increase ◽  
Reactive Component ◽  
Aqueous Synthesis ◽  
The Stability

α-Tricalcium phosphate (α-TCP) is an important reactive component in calcium phosphate bone cements which are used for the bone tissue regeneration and augmentation. By thermally treating amorphous calcium phosphate (ACP) at relatively low temperatures (650–900 °C), it is possible to obtain sub-micrometre or nanosized α-TCP particles. In the current research, it is shown that the aqueous synthesis environment where ACP is precipitated has significant influence on the stability of ACP and the α-TCP content in the thermally treated products. During ACP synthesis pH must be kept basic. While it is possible to synthesize ACP if potassium hydroxide or sodium hydroxide is used to raise the pH of synthesis, ammonium ions also must be present in the solution to obtain α-TCP after thermal treatment of ACP. If sodium hydroxide is used, higher α-TCP content is obtained (compare 89 % and 66 %). Increase of Ca/P ratio stabilizes ACP and allows to obtain products with high α-TCP content. Increase of both calcium and phosphate ion concentration in the synthesis destabilizes ACP and reduces the amount of α-TCP in the product (twofold increase reduced α-TCP content from 89% to 2%).

Surface Characteristics and Osteoinductivity of Biphasic Calcium Phosphate Ceramics with Different Sintering Temperature

2006 ◽  
Vol 309-311 ◽  
pp. 1299-1302 ◽  
Author(s):  
Hong Song Fan ◽  
Toshiyuki Ikoma ◽  
C.Y. Bao ◽  
H.L. Wang ◽  
Ling Li Zhang ◽  
...  
Keyword(s):  
Phase Composition ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Sintering Temperature ◽  
Surface Characteristics ◽  
Affecting Factors ◽  
Micro Structure ◽  
Factors Affecting ◽  
Distinct Temperature

Calcium phosphate (Ca-P) biomaterials have been proved to show osteoinductivity, however the affecting factors and mechanism are still unclear now. In this study, the surface characteristics of biphasic Ca-P ceramics (hydroxyapatite/tricalcium phosphate; HA/TCP) sintered at the distinct temperature were investigated and the mechanism of the osteoinductivity was discussed. The osteoinductivity of HA/TCP ceramics increased with decreasing the sintering temperature. The different surface micro-structure resulted from different sintering temperature includes phase composition, surface micro-structure, and surface potential. These characteristics should be the important factors affecting osteoinductivity.

Comparison of Biphasic Calcium Phosphate Bioceramics Fabricated Using Different Techniques

2011 ◽  
Vol 222 ◽  
pp. 255-258
Author(s):  
Kristine Salma ◽  
Zilgma Irbe ◽  
Dmitrijs Jakovlevs ◽  
Natalija Borodajenko ◽  
Liga Berzina-Cimdina
Keyword(s):  
Phase Composition ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Biphasic Calcium Phosphate ◽  
Mechanical Mixture ◽  
Preparation Technique ◽  
Homogeneous Microstructure ◽  
Intimate Mixture ◽  
Sintering Properties ◽  
Preparation Techniques

In this work three different preparation techniques of biphasic calcium phosphate (BCP) bioceramics (consisting of both hydroxyapatite (HAp) and β-tricalcium phosphate (TCP)) are compared: sintering of synthetic calcium-deficient apatites (CDAs) (intimate mixture of HAp and TCP - SBCP), sintering of mechanical mixture of synthetic HAp and apatitic tricalcium phosphate (Ap-TCP) - MBCP and sintering of mechanical mixture of synthetic HAp and calcium metaphosphate glass (CMG) - GBCP. Two different HAp/TCP phase ratios were investigated: 20/80 and 60/40. Phase composition, microstructure, sintering properties and microporosity of obtained BCP bioceramics were investigated. The open porosity of prepared BCP bioceramics is strongly influenced by phase composition and preparation technique. BCP bioceramics SBCP and MBCP have homogeneous microstructure, whereas GBCP has inhomogeneous inclusions of dense TCP. High content of hydroxyapatite (HAp) phase in MBCP and SBCP correlates with high microporosity.

scholarly journals The preparation and application of calcium phosphate biomedical composites in filling of weight-bearing bone defects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lijia Cheng ◽  
Tianchang Lin ◽  
Ahmad Taha Khalaf ◽  
Yamei Zhang ◽  
Hongyan He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Tricalcium Phosphate ◽  
Weight Bearing ◽  
Bone Defects ◽  
Type I ◽  
Artificial Bone ◽  
Thermosensitive Hydrogel ◽  
Bone Repairing ◽  
Histological Staining

AbstractNowadays, artificial bone materials have been widely applied in the filling of non-weight bearing bone defects, but scarcely ever in weight-bearing bone defects. This study aims to develop an artificial bone with excellent mechanical properties and good osteogenic capability. Firstly, the collagen-thermosensitive hydrogel-calcium phosphate (CTC) composites were prepared as follows: dissolving thermosensitive hydrogel at 4 °C, then mixing with type I collagen as well as tricalcium phosphate (CaP) powder, and moulding the composites at 37 °C. Next, the CTC composites were subjected to evaluate for their chemical composition, micro morphology, pore size, Shore durometer, porosity and water absorption ability. Following this, the CTC composites were implanted into the muscle of mice while the 70% hydroxyapatite/30% β-tricalcium phosphate (HA/TCP) biomaterials were set as the control group; 8 weeks later, the osteoinductive abilities of biomaterials were detected by histological staining. Finally, the CTC and HA/TCP biomaterials were used to fill the large segments of tibia defects in mice. The bone repairing and load-bearing abilities of materials were evaluated by histological staining, X-ray and micro-CT at week 8. Both the CTC and HA/TCP biomaterials could induce ectopic bone formation in mice; however, the CTC composites tended to produce larger areas of bone and bone marrow tissues than HA/TCP. Simultaneously, bone-repairing experiments showed that HA/TCP biomaterials were easily crushed or pushed out by new bone growth as the material has a poor hardness. In comparison, the CTC composites could be replaced gradually by newly formed bone and repair larger segments of bone defects. The CTC composites trialled in this study have better mechanical properties, osteoinductivity and weight-bearing capacity than HA/TCP. The CTC composites provide an experimental foundation for the synthesis of artificial bone and a new option for orthopedic patients.

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.

Raman spectroscopy of calcium phosphate glasses with varying calcium oxide modifier concentrations

1991 ◽  
Vol 3 (1) ◽  
pp. 195-200 ◽  
Author(s):  
Jeanne E. Pemberton ◽  
Lida Latifzadeh ◽  
Joseph P. Fletcher ◽  
Subhash H. Risbud
Keyword(s):  
Raman Spectroscopy ◽  
Calcium Phosphate ◽  
Calcium Oxide ◽  
Phosphate Glasses

Electrodeposition of MgO/Calcium Phosphate Composite Coatings on Titanium for Biomedical Applications

2013 ◽  
Vol 785-786 ◽  
pp. 872-876
Author(s):  
Yong Huang ◽  
Shu Guang Han ◽  
Ya Jing Yan ◽  
Xiao Feng Pang
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Calcium Phosphate ◽  
Biomedical Applications ◽  
Lower Layer ◽  
Composite Coatings ◽  
Polarization Test ◽  
Coated Surface ◽  
Bare Titanium ◽  
Superior Corrosion Resistance

This work elucidated corrosion resistance of the electrodeposited MgO/calcium phosphate (Ca-P/MgO) films on titanium (Ti). The microstructure, phase composition, and corrosion resistance of the films were studied. Results revealed that The Ca-P/MgO composite coatings were rough and inhomogeneous, the upper layer was floral-like crystals or flakes agglomerates morphology, and the lower layer was needle-like crystals which were mutually cross linked. The coating was very dense, and the content of Mg was about 0.3 wt%. Potentiodynamic polarization test manifested that the Ca-P/MgO-coated surface exhibited superior corrosion resistance than the bare titanium.

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