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. Biocompatibility Bioceramics' properties of being anticorrosive, biocompatible, and aesthetic make them quite suitable for medical usage. Zirconia ceramic has bioinertness and noncytotoxicity. Carbon is another alternative with similar mechanical properties to bone, and it also features blood compatibility, no tissue reaction, and non-toxicity to cells. Bioinert ceramics do not exhibit bonding with the bone, known as osseointegration. However, bioactivity of bioinert ceramics can be achieved by forming composites with bioactive ceramics. Bioactive ceramics, including bioglasses must be non-toxic, and form a bond with bone. In bone repair applications, i.e. scaffolds for bone regeneration, the solubility of bioceramics is an important parameter, and the slow dissolution rate of most bioceramics relative to bone growth rates remains a challenge in their remedial usage. Unsurprisingly, much focus is placed on improving dissolution characteristics of bioceramics while maintaining or improving their mechanical properties. Glass ceramics elicit osteoinductive properties, with higher dissolution rates relative to crystalline materials, while crystalline calcium phosphate ceramics also exhibit non-toxicity to tissues and bioresorption. The ceramic particulate reinforcement has led to the choice of more materials for implant applications that include ceramic/ceramic, ceramic/polymer, and ceramic/metal composites. Among these composites ceramic/polymer composites have been found to release toxic elements