Abstract
Hydroxyapatite (HA) is the main mineral component of bone tissue, representing ca. 69 vol% in bone and up to 98 vol% in dental enamel. Its chemical composition close to the mineral phase of bone is the origin of its excellent biocompatibility to tissue bone. Hydroxyapatite has been applied in orthopaedics as block implants, porous, granules and coating material, either dense or porous. However, the application is restricted to non-load bearing application due to its brittleness and low toughness and flexural strength. With this, the development of bioactive dense HA is necessary as it has promising potential in application of load bearing bone implant. Few efforts have been made in developing many methods to produce dense HA. Some of the methods have been combined to prepare dense HA with improved properties. This paper will be discussing the recent progress on efforts which have been done in improving mechanical properties of hydroxyapatite-based dense type biomaterials for load bearing bone substitutes applications. Some recent patents related to dense calcium phosphate are also reviewed.
Keywords: Hydroxyapatite, dense, preparation, bone substitutes, review, Biomaterials, bone tissue,, dental enamel, biocompatibility, orthopaedics, flexural strength, bioactive dense, dense calcium phosphate, calcium phosphates, crystallographic structure, polymer-ceramic composite material, maxillofacial surgery, bony consolidation, periodontal lesion filling, skeletons, bone implants, bio-inert implants, bioactive ceramics, BONE, collagen fibres, inorganic, bone mineral, fracture toughness, physicochemical structure, cortical bone, cancellous bone, articular, corrosion, cobalt-chromium alloys, adverse reactions, inflammation, cytoto-xicity, carcinogenesis, wear resistance, prosthetic device, hip implant, vascular graft, knee prostheses, fixation wires, Hip replacement prostheses, Ti-alloy, titanium, cobalt-based alloys, vanadium, orthopaedic prostheses, resistant polymer, hip joint prosthesis, carbon fiber, cardiovascular devices, augmentation, soft tissues, drug delivery systems, tissue engineering, middle ear implants, heart valves, physiological environment, dissolution, osteoclasts, femoral stem, femoral head, acetabular cup, coefficient of friction, cold-work-ing process, Conventional Biomedical Implants, inert bioceramics, in vitro studies, cytotoxic effects, biomedical coatings, bone-implant interface, iron-based alloys, allergens, carcino-gens, corrosion attacks, orthopaedic surgery, Alumina (Al2O3), zirconia (ZrO2), artifi-cial bones, artificial teeth roots, simulating, osseoconduction, HA, ’, s brittleness, HA deficiencies, induce energy dissipative mechanisms, crack deflection, (D, L-lactic-co-glycolic acid), poly (L-lactic acid), osteointegration kinetics, tricalcium phosphates (TCP), calcination., nanometer scale, phase uniformity, chemical homogeneity, gene, protein delivery devices, phosphate colloidal suspension, maxillo-facial, dental defects, oxyapatite, Novel dental enamel, gas foaming particle leaching method, osteogenic qualities, chemosynthetic, Novel technology, growth simulator, surgical stomatology, traumatology, articulating surface, sol-gel-containing material, alveolar ridge augmentation, small bone parts, maxilla facial recons-truction, bone regeneration, calcifying solution, wet-chemical method, hydrothermal, chemical precipitation, solid state reaction, pressurized dense bodies, slip casting, tape-casting, injection moulding, viscous plastic, processing, centrifugal settling, densification, cold isostatic pressing (CIP), X-ray diffraction analysis, compaction pressures, sintering temperature, sintered density, grain size, grain size distribution, porosity, agglomerates, Young's Modulus, cold isostatic pressing, bulk density, Vickers method, theoretical density, sintering method, relative density, median crack system, equiaxed fine grains, sintered dense bodies, pulp-capping materials, alveolar ridge resorption, morphology, calcinations, bone matrix, tensile strength of bone, cell surface ligands, biphasic calcium phosphate (BCP), polymer-matrix composite (PMC), carbon nanotubes (CNTs), cement-type reaction involving, calcium phosphate cements, crystalline calcium orthophosphate powder, X-ray diffraction patterns
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