Limits...
Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements.

Gallinetti S, Canal C, Ginebra MP, Ferreira J - J Am Ceram Soc (2014)

Bottom Line: However, they have some limitations associated to their condition of high-temperature ceramics.The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area.Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements.

View Article: PubMed Central - PubMed

Affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC) Barcelona, 08028, Spain ; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) Barcelona, Spain ; Center for Research in Nanoengineering (CRnE), UPC Barcelona, 08028, Spain.

ABSTRACT

Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca(2+) release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media.

No MeSH data available.


Related in: MedlinePlus

X-Ray diffraction patterns of α-TCP (a) and β-TCP (b); particle size distribution of α-TCP (c) and β-TCP (d) powders. The curve indicates the cumulative volume with focus on 50% (median) and the bars correspond to the differential volume of particles.
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fig01: X-Ray diffraction patterns of α-TCP (a) and β-TCP (b); particle size distribution of α-TCP (c) and β-TCP (d) powders. The curve indicates the cumulative volume with focus on 50% (median) and the bars correspond to the differential volume of particles.

Mentions: The XRD patterns of the α-TCP and β-TCP powders are shown in Fig. 1, together with their particle size distribution, as determined by laser diffraction. The two powders consisted mostly of α-TCP (94.9%) and β-TCP (97.5%). The presence of amorphous phase was estimated to be below the limit of detection (1%) in both cases. The granulometric parameters of the powders are summarized in Table I along with the SSA values.


Development and Characterization of Biphasic Hydroxyapatite/β-TCP Cements.

Gallinetti S, Canal C, Ginebra MP, Ferreira J - J Am Ceram Soc (2014)

X-Ray diffraction patterns of α-TCP (a) and β-TCP (b); particle size distribution of α-TCP (c) and β-TCP (d) powders. The curve indicates the cumulative volume with focus on 50% (median) and the bars correspond to the differential volume of particles.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4384943&req=5

fig01: X-Ray diffraction patterns of α-TCP (a) and β-TCP (b); particle size distribution of α-TCP (c) and β-TCP (d) powders. The curve indicates the cumulative volume with focus on 50% (median) and the bars correspond to the differential volume of particles.
Mentions: The XRD patterns of the α-TCP and β-TCP powders are shown in Fig. 1, together with their particle size distribution, as determined by laser diffraction. The two powders consisted mostly of α-TCP (94.9%) and β-TCP (97.5%). The presence of amorphous phase was estimated to be below the limit of detection (1%) in both cases. The granulometric parameters of the powders are summarized in Table I along with the SSA values.

Bottom Line: However, they have some limitations associated to their condition of high-temperature ceramics.The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area.Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements.

View Article: PubMed Central - PubMed

Affiliation: Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC) Barcelona, 08028, Spain ; Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) Barcelona, Spain ; Center for Research in Nanoengineering (CRnE), UPC Barcelona, 08028, Spain.

ABSTRACT

Biphasic calcium phosphate bioceramics composed of hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) have relevant properties as synthetic bone grafts, such as tunable resorption, bioactivity, and intrinsic osteoinduction. However, they have some limitations associated to their condition of high-temperature ceramics. In this work self-setting Biphasic Calcium Phosphate Cements (BCPCs) with different HA/β-TCP ratios were obtained from self-setting α-TCP/β-TCP pastes. The strategy used allowed synthesizing BCPCs with modulated composition, compressive strength, and specific surface area. Due to its higher solubility, α-TCP was fully hydrolyzed to a calcium-deficient HA (CDHA), whereas β-TCP remained unreacted and completely embedded in the CDHA matrix. Increasing amounts of the non-reacting β-TCP phase resulted in a linear decrease of the compressive strength, in association to the decreasing amount of precipitated HA crystals, which are responsible for the mechanical consolidation of apatitic cements. Ca(2+) release and degradation in acidic medium was similar in all the BCPCs within the timeframe studied, although differences might be expected in longer term studies once β-TCP, the more soluble phase was exposed to the surrounding media.

No MeSH data available.


Related in: MedlinePlus