small change in the Ca/P ratio of HA especially caused by substitution of ions can

have a remarkable effect on its properties. In addition, there can be a noticeable

effect on the crystallinity of nanopowder by ionic substitution in HA and its heat

treatment. These changes are helpful when such nanopowders are used as drug

release agents, bone grafts, and bone void fillers to deal with various diseases related

to bone infections and injuries. Furthermore, the coatings on implants with ionic

substituted HAs also show a great future potential in the protection of biodegradable

metallic implants. Interestingly, many researchers have proposed that the ionic

substituted HA mimic the natural bone, but their results are far from reality and

mimicking of real composition of bone is still not achieved. The natural bone

constitutes various trace ions, but the fact is that only one or two ions have been

incorporated simultaneously in ionic substituted HAs.

Nevertheless, human bone has high magnesium amount, and it has more

biological relevance, but a comprehensive study on its substitution is not available.

Although human bone contains a very small amount of Sr, an extensive study on its

substitution is reported in the literature. Besides this, various ions like Na, K, etc. are

Fig. 23.12 ZnFHA coated 316L SS after immersion in SBF

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Unleashing Potential of Bone Mimicking Nanodimensional Hydroxyapatites and. . .

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