A titanium hip prosthesis, with a ceramic head and polyethylene acetabular cup Ceramics are now commonly used in the medical fields as dental and bone implants. Surgical cermets are used regularly. Joint replacements are commonly coated with<unk>  materials to reduce wear and inflammatory response. Other examples of medical uses for<unk> s are in pacemakers, kidney dialysis machines, and respirators. The global demand on medical ceramics and ceramic components was about U.S. $9.8 billion in 2010. It was forecast to have an annual growth of 6 to 7 percent in the following years, with world market value predicted to increase to U.S. $15.3 billion by 2015 and reach U.S. $18.5 billion by 2018. Mechanical properties and composition<unk> s are meant to be used in extracorporeal circulation systems (dialysis for example) or engineered bioreactors; however, they're most common as implants. Ceramics show numerous applications as biomaterials due to their physico-chemical properties. They have the advantage of being inert in the human body, and their hardness and resistance to abrasion makes them useful for bones and teeth replacement. Some ceramics also have excellent resistance to friction, making them useful as replacement materials for malfunctioning joints. Properties such as appearance and electrical insulation are also a concern for specific biomedical applications. Some<unk> s incorporate alumina (Al2O3) as their lifespan is longer than that of the patient's. The material can be used in middle ear ossicles, ocular prostheses, electrical insulation for pacemakers, catheter orifices and in numerous prototypes of implantable systems such as cardiac pumps. Aluminosilicates are commonly used in dental prostheses, pure or in ceramic-polymer composites. The ceramic-polymer composites are a potential way to filling of cavities replacing amalgams suspected to have toxic effects. The aluminosilicates also have a glassy structure. Contrary to artificial teeth in resin, the colour of tooth ceramic remains stable Zirconia doped with yttrium oxide has been proposed as a substitute for alumina for osteoarticular prostheses. The main advantages are a greater failure strength, and a good resistance to fatigue. Vitreous carbon is also used as it is light, resistant to wear, and compatible with blood. It is mostly used in cardiac valve replacement. Diamond can be used for the same application, but in coating form. Calcium phosphate-based ceramics constitute, at present, the preferred bone substitute material in orthopaedic and maxillofacial applications, as they are similar to the main mineral phase of bone in structure and chemical composition. Such synthetic bone substitute or scaffold materials are typically porous, which provides an increased surface area that encourages osseointegration, involving cell colonisation and revascularisation. However, such porous materials generally exhibit lower mechanical strength compared to bone, making highly porous implants very delicate. Since the elastic modulus values of ceramic materials are generally higher than that of the surrounding bone tissue, the implant can cause mechanical stresses at the bone interface. Calcium phosphates usually found in<unk> s include hydroxyapatite (HAP) Ca10(PO4)6(OH)2; tricalcium phosphate β (β TCP): Ca3 (PO4)2; and mixtures of HAP and β TCP. Table 1:<unk> s Applications Devices Function Biomaterial Artificial total hip, knee, shoulder, elbow, wrist Reconstruct arthritic or fractured joints High-density alumina, metal bioglass coatings Bone plates, screws, wires Repair fractures Bioglass-metal fibre composite, Polysulphone-carbon fibre composite Intramedullary nails Align fractures Bioglass-metal fibre composite, Polysulphone-carbon fibre composite Harrington rods Correct chronic spinal curvature Bioglass-metal fibre composite, Polysulphone-carbon fibre composite Permanently implanted artificial limbs Replace missing extremities Bioglass-metal fibre composite, Polysulphone-carbon fibre composite Vertebrae Spacers and extensors Correct congenital deformity Al2O3 Spinal fusion Immobilise vertebrae to protect spinal cord Bioglass Alveolar bone replacements, mandibular reconstruction Restore the alveolar ridge to improve denture fit Polytetra fluro ethylene (PTFE) - carbon composite, Porous Al2O3, Bioglass, dense-apatite End osseous tooth replacement implants Replace diseased, damaged or loosened teeth Al2O3, Bioglass, dense hydroxyapatite, vitreous carbon Orthodontic anchors Provide posts for stress application required to change deformities Bioglass-coated Al2O3, Bioglass coated vitallium Table 2: Mechanical Properties of Ceramic Biomaterials Material Young's Modulus (GPa) CompressiveStrength (MPa) Bond strength (GPa) Hardness Density (g/cm3) Inert Al2O3 380 4000 300-400 2000-3000(HV) >3.9 ZrO2 (PS) 150-200 2000 200-500 1000-3000(HV) ≈6.0 Graphite 20-25 138 NA NA 1.5-1.9 (LTI)Pyrolitic Carbon 17-28 900 270-500 NA 1.7-2.2 Vitreous Carbon 24-31 172 70-207 150-200(DPH) 1.4-1.6 Bioactive HAP 73-117 600 120 350 3.1 Bioglass ≈75 1000 50 NA 2.5 AW Glass Ceramic 118 1080 215 680 2.8 Bone 3-30 130-180 60-160 NA NA Multipurpose A number of implanted ceramics have not actually been designed for specific biomedical applications. However, they manage to find their way into different implantable systems because of their properties and their good biocompatibility. Among these ceramics, we can cite silicon carbide, titanium nitrides and carbides, and boron nitride. TiN has been suggested as the friction surface in hip prostheses. While cell culture tests show a good biocompatibility, the analysis of implants shows significant wear, related to a delaminating of the TiN layer. Silicon carbide is another modern-day ceramic which seems to provide good biocompatibility and can be used in bone implants. Specific use In addition to being used for their traditional properties, bioactive ceramics have seen specific use for due to their biological activity. Calcium phosphates, oxides, and hydroxides are common examples. Other natural materials — generally of animal origin — such as bioglass and other composites feature a combination of mineral-organic composite materials such as HAP, alumina, or titanium dioxide with the biocompatible polymers (polymethylmethacrylate): PMMA, poly(L-lactic) acid: PLLA, poly(ethylene). Composites can be differentiated as bioresorbable or non-bioresorbable, with the latter being the result of the combination of a bioresorbable calcium phosphate (HAP) with a non-bioresorbable polymer (PMMA, PE). These materials may become more widespread in the future, on account of the many combination possibilities and their aptitude at combining a biological activity with mechanical properties similar to those of the bone.
Bioceramic
Bioactive glass
Biopharmaceutical
Covid-Organics
Biomaterial
Inhalant
Mold
Cathartic