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 ...
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...
Co-doped hydroxyapatites as potential materials for biomedical applications
Hydroxyapatite (HA) is a synthetic biomaterial resembling the composition of mammalian hard tissue and thus, it is widely employed as a bone graft material, hard tissue engineering scaffold and coating layer for metallic substrates. Biological apatite is non-stoichiometric in nature. It is composed of small crystals and characterized by poor crystallinity and relatively high solubility with respect to stoichiometric HA. Chemical compositions of these crystals consist of Ca, P and trace amounts of various io...
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 of calcium carbonate particles for biomedical applications
Oral, Çağatay Mert; Ercan, Batur; Department of Metallurgical and Materials Engineering (2020)
Calcium carbonate (CaCO3) particles have been widely used in biomedical applications owing to their biocompatibility and biodegradability. In order to effectively utilize CaCO3 particles in biomedical applications, their physical and chemical properties should be systematically controlled. However, this is a challenging task due to the presence of three different anhydrous CaCO3 polymorphs having complex crystallization behavior. In this thesis, CaCO3 particles were synthesized at distinct environments to c...
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: