present in the biological apatite, but these are not substituted in HA intentionally. In

addition, the research on ionic substitution seems to be motivated by the possible

therapeutic role of ions rather than materials characterization.

It is recommended that an extensive work should be carried out on ionic

substituted HAs to fully exploit their potential. Some future scope in this field

includes the following aspects:

•

Comparison of ionic substituted HAs with stoichiometric HA.

•

Effect of different ions on the structure and properties of HA should be compared.

•

Composition close to natural apatite should be synthesized.

•

Experiments on in vivo examination need to be enhanced.

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