Hydroxyapatite is a key academic concept and subject of research primarily within materials science, biomaterials, and biomedical engineering, focused on the study of the naturally occurring calcium phosphate mineral (Ca₁₀(PO₄)₆(OH)₂) that constitutes the main inorganic component of bone and teeth. Research into hydroxyapatite investigates its synthesis, structure, properties (such as biocompatibility and bioactivity), and diverse applications, particularly in tissue engineering, drug delivery, and dental materials, due to its close resemblance to biological hard tissues.