Hydroxyapatite (HA)

Hydroxyapatite (HA) is a calcium phosphate ceramic with a chemical composition that closely mimics the mineral phase of natural bone and tooth enamel, making it biocompatible and osteoconductive. It is the primary ceramic material in orthopedic and dental applications, where it is used as a coating on metal implants, in bone scaffolds, and as a standalone filler to promote bone regeneration and integration with living tissue. Engineers select HA over purely metallic alternatives because its chemical similarity to bone reduces inflammation and accelerates osseointegration, though its brittle nature and lower fracture toughness compared to metals typically restrict it to non-load-bearing roles or composite reinforcement.