When selecting hydroxyapatite powder for biomedical applications, several factors must be considered to ensure optimal performance and compatibility with human tissue. These include: Purity and Composition: High purity and correct stoichiometry are crucial to mimic the natural bone mineral closely. Particle Size and Morphology: The size and shape of the HA particles can significantly affect the material's bioactivity and osseointegration capabilities. Crystallinity: The degree of crystallinity impacts the solubility and mechanical strength of HA, with more crystalline materials being less soluble and stronger, suitable for load-bearing applications. Sterility: For implantable applications, the HA powder must be sterile to prevent infection. Understanding these factors is essential for developing effective and safe hydroxyapatite-based products for medical and dental use.