5. Conclusion

In view of the latest advances in the field of bone substitutes, three main avenues for the development of calcium phosphate-based biomaterials should be pursued in the future: their composition, their form, and their association with bioactive agents or cells.

Firstly, recent decades have seen the emergence of substituted calcium phosphates (e.g. silicate apatites or zinc-doped tricalcium phosphate) or, more generally, calcium phosphates chemically modified to enhance their biological properties. This route to enhancing and controlling the biological activity of CaP-based biomaterials is likely to be further developed with other types of ions/substituents and different combinations of possible substituents. Another avenue of development is based on exploiting the reactivity and surface properties of nanocrystalline apatites analogous to bone mineral, in particular...