A calcium phosphate with the formula Ca₁₀(PO₄)₆(OH)₂. Close to the mineral component of bones and teeth, it is used as a bioactive ceramic that bonds directly to bone. Its Ca/P ratio is 1.67.
Japanese name: ハイドロキシアパタイト
Hydroxyapatite appears in 3 practice questions across 1 topic, including Biomaterials.
Field: Biomaterials
Answer: C. 1.67
The formula contains 10 Ca and 6 P (from the 6 PO₄ groups), so Ca/P = 10/6 ≈ 1.67. Bone apatite contains carbonate ions and other species, and its Ca/P is somewhat lower than this. 1.50 is the ratio 3/2 of tricalcium phosphate (TCP, Ca₃(PO₄)₂). β-TCP is more soluble than hydroxyapatite and is used as a bioresorbable material that is resorbed in the body and replaced by bone. 1.33 is the ratio 8/6 of octacalcium phosphate (Ca₈H₂(PO₄)₆·5H₂O). If the Ca/P ratio of a synthesized powder deviates from 1.67, β-TCP or CaO forms as a by-product on firing, so controlling the composition is important.
β-TCP is more soluble than hydroxyapatite and is used as a bioresorbable material that is resorbed in the body and replaced by bone.
What is the Ca/P molar ratio of hydroxyapatite, Ca₁₀(PO₄)₆(…Hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂) is a calcium phosphate with nearly the same composition as the mineral component of bones and teeth; in the body a layer of the same kind of apatite as bone forms on its surface, and it bonds directly to bone.
Which of these is a bioactive ceramic that bonds directly a…The term mainly expresses direct contact with bone, as distinct from chemical bonding such as that of hydroxyapatite.
Which statement correctly describes osseointegration, as th…Osseointegration Passivity Bone cement Biocompatibility Biodegradable polymer Stress shielding Superelasticity β titanium alloy