An improvement in sintering property of β-tricalcium phosphate by addition of calcium pyrophosphate

A macroporous phosphate invert glass ceramic (PIGC) was prepared by dipping polymer sponges in the powder-slurry of the mother glass with a composition of 60CaO-30P2O-3TiO2- 7Na2O in mol%, and subsequent burning off the sponge at 850°C for 1 hr. The macroporous PIGC consists predominantly of ß-tricalcium phosphate (β-TCP) and ß-calcium pyrophosphate, and it has macropores of 500 μm in diameter and porosity of 83 %. Its compressive strength was estimated to be 160 kPa. The PIGC composite containing a large amount of β-TCP was also prepared by heating the mixture of Ca(OH)2 with the mother glass powders of the PIGC. Solubility of the composite was higher than PIGC. The macroporous PIGC and PIGC composite were expected to be applicable in high resorbable scaffolds for bone tissue engineering.

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An Improvement in Sintering Property of β-Tricalcium Phosphate by Addition of Calcium Pyrophosphate and Calcium Carbonate

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.2359 ◽

2005 ◽

Vol 475-479 ◽

pp. 2359-2362 ◽

Cited By ~ 3

Author(s):

Xin Long Wang ◽

Hong Song Fan ◽

Xing Dong Zhang

Keyword(s):

Phase Transition ◽

Compressive Strength ◽

Calcium Carbonate ◽

Tricalcium Phosphate ◽

Degradation Rate ◽

Calcium Pyrophosphate ◽

Sintering Behavior ◽

Second Phase ◽

Lower Temperature

b-tricalcium phosphate(TCP, Ca3(PO4)2) ceramics are preferred as a bioceramics because of its chemical stability and reasonable degradation rate in vivo, but it is difficult to obtain b-TCP ceramics with high compressive strength at lower temperature than that of phase transition to a-TCP. In this study, the sintering behavior of TCP, Ca2P2O7-doped TCP, and CaCO3-doped TCP in the range of 2wt%~5wt% were investigated respectively. Phase transition of pure TCP took place between 1100°C to 1150°C, and pure b-TCP ceramics could achieve a compressive strength of only 3MPa. However, calcium pyrophosphate (CPP, Ca2P2O7) additive prevented the transformation of b-TCP to a-TCP, but the second phase of CPP was observed in the resultant ceramics. Phase transition of TCP ceramics by addition of both CPP and calcium carbonate (CC, CaCO3) took place between 1200°C to 1250°C and the resultant TCP ceramics had few impurity of CPP. By adding CPP and CC to TCP, final ceramics with compressive strength over 12MPa could be obtained when sintered at 1200°C for 2hrs.

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Evaluation of α-Tricalcium Phosphate Cement Obtained at Different Temperatures

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.1187 ◽

2012 ◽

Vol 727-728 ◽

pp. 1187-1192 ◽

Cited By ~ 2

Author(s):

Rafaela Silveira Vieira ◽

Wilbur Trajano Guerin Coelho ◽

Mônica Beatriz Thürmer ◽

Juliana Machado Fernandes ◽

Luis Alberto Santos

Keyword(s):

Calcium Phosphate ◽

Tricalcium Phosphate ◽

Setting Time ◽

Calcium Pyrophosphate ◽

In Vitro Test ◽

Calcium Phosphate Cements ◽

Similar Chemical ◽

Different Temperatures ◽

Vitro Test

The calcium phosphate cements (CPCs) based on α-tricalcium phosphate (α-TCP) are highly attractive for use in medicine and odontology, since they have similar chemical and phase composition of mineral phase of bones (calcium deficient hydroxyapatite (CDHA)). However, one of the biggest difficulties for use of this type of cement is its low mechanical strength due to the presence of undesirable phases, such as β-tricalcium phosphate. The route for obtaining α-TCP is at high temperature by solid state reaction, mixing calcium carbonate and calcium pyrophosphate. The aim of this work was to obtain calcium phosphate cements with improved strength, by studying the obtaining of α-TCP at temperatures of 1300, 1400 and 1500°C. The samples were analyzed by crystalline phases, pH, setting time, particle size, in vitro test (Simulated Body Fluid), porosity, density and compressive strength. The results show that the synthesis temperatures influence strongly the phases of powders obtained and the mechanical properties of cement, being unnecessary quenching for obtaining pure α-TCP.

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MODIFICATION OF CALCIUM PHOSPHATE FOAM CERAMICS WITH BIOAPATITE IN SBF SOLUTION

Physical and Chemical Aspects of the Study of Clusters Nanostructures and Nanomaterials ◽

10.26456/pcascnn/2021.13.870 ◽

2021 ◽

pp. 870-880

Author(s):

Валентина Константиновна Крутько ◽

Любовь Юрьевна Маслова ◽

Ольга Николаевна Мусская ◽

Татьяна Викторовна Сафронова ◽

Анатолий Иосифович Кулак

Keyword(s):

Calcium Phosphate ◽

Polyurethane Foam ◽

Tricalcium Phosphate ◽

Calcium Pyrophosphate ◽

Static Strength ◽

Sbf Solution

Получена многофазная кальцийфосфатная пенокерамика, представленная Д -трикальцийфосфатом (65 %) и Д -пирофосфатом кальция (25 %), включающая гидроксиапатит ( 5 %) и а -трикальцийфосфат ( 5 %), пористостью 60 - 64 % со сквозной архитектурой пенополиуретана. Нанесение слоя гидроксиапатита приводило к увеличению содержания гидроксиапатита до 25 %, а -трикальцийфосфата до 40 %, и повышению статической прочности до 0,03 МПа при снижении пористости до 49 %. Нанесение второго слоя гидроксиапатита способствовало повышению содержания гидроксиапатита до 40 %, статическая прочность достигала 0,05 МПа при пористости 40%. Формирование биоапатита в виде слоя «пеносфер» размером от 2 до 10 мкм происходило в процессе модифицирования всех видов пенокерамики в растворе SBF в течение 21 - 28 суток. Модифицированная кальцийфосфатная пенокерамика, обогащенная а -трикальцийфосфатом и гидроксиапатитом, характеризовалась максимальной статической прочностью 0,08 МПа при пористости 38%. The multiphase calcium phosphate foam ceramics, represented by р -tricalcium phosphate (65 %) and р -calcium pyrophosphate (25 %), including hydroxyapatite (5 %) and а -tricalcium phosphate (5%), with 60 - 64% porosity and a through architecture of polyurethane foam was obtained. The application of a layer of hydroxyapatite led to an increase in the content of hydroxyapatite to 25 %, а -tricalcium phosphate to 40%, and an increase in static strength to 0,03 MPa with a decrease in porosity to 49%. The application of the second layer of hydroxyapatite promoted an increase in the content of hydroxyapatite to 40%, the static strength reached 0,05 MPa at a porosity 40 %. The bioapatite formation in the shape of «foam spheres» with a size from 2 to 10 pm occurred in the process of modifying all types of foam ceramics in a SBF solution during 21 - 28 days. The modified calcium phosphate foam ceramics enriched with а -tricalcium phosphate and hydroxyapatite, was characterized by the maximum static strength 0,08 MPa at a porosity 38 %.

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Effect of minor amounts of β-calcium pyrophosphate and hydroxyapatite on the physico-chemical properties and osteoclastic resorption of β-tricalcium phosphate cylinders

Bioactive Materials ◽

10.1016/j.bioactmat.2021.09.003 ◽

2021 ◽

Author(s):

B. Le Gars Santoni ◽

L. Niggli ◽

S. Dolder ◽

O. Loeffel ◽

G.A. Sblendorio ◽

...

Keyword(s):

Tricalcium Phosphate ◽

Chemical Properties ◽

Calcium Pyrophosphate ◽

Physico Chemical ◽

Osteoclastic Resorption

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Influence of Mg-doping, calcium pyrophosphate impurities and cooling rate on the allotropic α ↔ β-tricalcium phosphate phase transformations

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2015.09.037 ◽

2016 ◽

Vol 36 (3) ◽

pp. 817-827 ◽

Cited By ~ 32

Author(s):

P.M.C. Torres ◽

J.C.C. Abrantes ◽

A. Kaushal ◽

S. Pina ◽

N. Döbelin ◽

...

Keyword(s):

Phase Transformations ◽

Cooling Rate ◽

Tricalcium Phosphate ◽

Calcium Pyrophosphate ◽

Mg Doping ◽

Phosphate Phase

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Hydrogen-substituted β-tricalcium phosphate synthesized in organic media

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616015675 ◽

2016 ◽

Vol 72 (6) ◽

pp. 875-884 ◽

Cited By ~ 8

Author(s):

Christoph Stähli ◽

Jürg Thüring ◽

Laëtitia Galea ◽

Solène Tadier ◽

Marc Bohner ◽

...

Keyword(s):

Tricalcium Phosphate ◽

Inductively Coupled Plasma ◽

Bone Substitutes ◽

Calcium Pyrophosphate ◽

X Ray Diffraction ◽

Synthesis Conditions ◽

Inductively Coupled ◽

Ca Substitution ◽

Crystal Model ◽

Quantitative Verification

β-Tricalcium phosphate (β-TCP) platelets synthesized in ethylene glycol offer interesting geometries for nano-structured composite bone substitutes but were never crystallographically analyzed. In this study, powder X-ray diffraction and Rietveld refinement revealed a discrepancy between the platelet structure and the known β-TCP crystal model. In contrast, a model featuring partial H for Ca substitution and the inversion of P1O4tetrahedra, adopted from the whitlockite structure, allowed for a refinement with minimal misfits and was corroborated by HPO42−absorptions in Fourier-transform IR spectra. The Ca/P ratio converged to 1.443 ± 0.003 (n= 36), independently of synthesis conditions. As a quantitative verification, the platelets were thermally decomposed into hydrogen-free β-TCP and β-calcium pyrophosphate which resulted in a global Ca/P ratio in close agreement with the initial β-TCP Ca/P ratio (ΔCa/P = 0.003) and with the chemical composition measured by inductively coupled plasma (ΔCa/P = 0.003). These findings thus describe for the first time a hydrogen-substituted β-TCP structure,i.e.a Mg-free whitlockite, represented by the formula Ca21 − x(HPO4)2x(PO4)14 − 2x, wherex= 0.80 ± 0.04, and may have implications for resorption properties of bone regenerative materials.

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Degradation Behavior of β-Ca3 (PO4)2/β-Ca2P2O7 Bioceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.1650 ◽

2007 ◽

Vol 336-338 ◽

pp. 1650-1653

Author(s):

Yuan Yuan Li ◽

De An Yang ◽

Hong Zhao

Keyword(s):

Weight Loss ◽

Tricalcium Phosphate ◽

Bone Substitute ◽

Calcium Pyrophosphate ◽

Degradation Behavior ◽

Before And After

β-tricalcium phosphate (β-TCP) added with certain amounts of β-calcium pyrophosphate (β-CPP) was prepared. Degradation behavior of β-TCP/β-CPP ceramic was tested by soaking in Tris solution for 20d. The morphologies of composites before and after degradation were observed by SEM. The weight loss was tested after soaking in immersion solution. The results showed that the β-TCP/β-CPP ceramic had great potential as a biodegradable bone substitute.

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