Manufacture of macroporous calcium hydroxyapatite bioceramics

Engin, NO
Tas, AC
Trabecular bones of almost all vertebrate organisms basically consist of macroporous (55-70% interconnected porosity) bone mineral, i.e. calcium hydroxyapatite (HA: Ca-10(PO4)(6)(OH)(2)). The macroporosity observed in the trabecular bones then allows the ingrowth of the soft tissues and organic cells into the bone matrix. Sub-micron, chemically uniform, and high phase-purity HA powders produced in our laboratory were mixed, under vigorous ultrasonification, with methyl cellulose of appropriate amounts in the form of an aqueous slurry of proper viscosity and thickness. The ceramic cakes produced in this way were then slowly dried in an oven in the temperature range of 50-90 degrees C. Dried cakes of porous HA were physically cut into various prismatic shapes. These parts were then slowly heated in an air atmosphere to the optimum sintering temperature of 1250 degrees C. The HA bioceramic parts obtained by this novel 'foaming technique' were found to have tractable and controllable interconnected porosity in the range of 60-90%, with typical pore sizes ranging from 100-250 microns. Sample characterization was mainly achieved by scanning electron microscopy (SEM) studies and three-point bending tests.


Preparation of porous Ca-10(PO4)(6)(OH)(2) and beta-Ca-3(PO4)(2) bioceramics
Engin, NO; Tas, AC (2000-07-01)
Submicrometer-sized, pure calcium hydroxyapatite (HA, (Ca-10(PO4)(6)(OH)(2))) and eta-tricalcium phosphate (beta-TCP, Ca-3(PO4)(2)) bioceramic powders, that have been synthesized via chemical precipitation techniques, were used in the preparation of aqueous slurries that contained methyl cellulose to manufacture porous (70%-95% porosity) HA or beta-TCP ceramics. The pore sizes in HA bioceramics of this study were 200-400 mu m, whereas those of beta-TCP bioceramics were 100-300 mu m. The pore morphology and ...
Chemical preparation of carbonated calcium hydroxyapatite powders at 37 degrees C in urea-containing synthetic body fluids
Bayraktar, D; Tas, AC (1999-01-01)
An important inorganic phase of synthetic bone applications, calcium hydroxyapatite (HA, Ca-10(PO4)(6)(OH)(2)), was prepared as a single-phase ceramic powder. Carbonated HA powders were formed from calcium nitrate tetrahydrate and diammonium hydrogen phosphate salts dissolved in aqueous 'synthetic body fluid' (SBF) solutions, containing urea (H2NCONH2), at 37 degrees C and pH of 7.4, by using a novel chemical precipitation technique. These powders were also found to contain trace amounts of Na and Mg impuri...
Synthesis and characterization of whitlockite from sea urchin skeleton and investigation of antibacterial activity
Yucel, Aysegul; Sezer, Selda; BİRHANLI, EMRE; Ekinci, Tuba; Yalman, Emine; Depci, Tolga (2021-01-01)
In the present study, undoped whitlockite and ZnO doped-Whitlockite, which is the second most abundant inorganic material in bone structure, were synthesized from sea urchin skeleton. The obtained bioceramic ma-terials were characterized by XRD, FT-IR, and SEM and their antibacterial activities were determined using the inhibition zone diameters of Escherichia coli and Pseudomonas aeruginosa as gram negative bacteria and Staphylococcus aureus as gram positive bacterium after 24 h incubation. The characteriz...
Prediction of hexagonal lattice parameters of stoichiometric and non-stoichiometric apatites by artificial neural networks
Koçkan, Ümit; Evis, Zafer; Department of Micro and Nanotechnology (2009)
Apatite group of minerals have been widely used in applications like detoxification of wastes, disposal of nuclear wastes and energy applications in addition to biomedical applications like bone repair, substitution, and coatings for metal implants due to its resemblance to the mineral part of the bone and teeth. X-ray diffraction patterns of bone are similar to mineral apatites such as hydroxyapatite and fluorapatite. Formation and physicochemical properties of apatites can be understood better by computer...
Synthesis and sintering of B, Sr, Mg multi-doped hydroxyapatites: Structural, mechanical and biological characterization
Yedekçi, Buşra; Tezcaner, Ayşen; DEMİR, TEYFİK; Evis, Zafer (2021-03-01)
Hydroxyapatite (HA, Ca-10(PO4)(6)(OH)(2)) is the main constituent mineral of bone and teeth in mammals. Due to its outstanding biocompatibility and osteoconductive capabilities, it is preferred for bone repair and replacement. Owing to high potential to have excellent biological properties, ternary ions-doped HAs have just begun to be investigated in the biomedical field and preparing multi-doped HAs is a fairly new approach. Boron (B, BO33-), strontium (Sr, Sr2+) and magnesium (Mg, Mg2+) provide a benefici...
Citation Formats
N. Engin and A. Tas, “Manufacture of macroporous calcium hydroxyapatite bioceramics,” JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, pp. 2569–2572, 1999, Accessed: 00, 2020. [Online]. Available: