Synthesis and Characterization of Hydroxyapatite Nanocoatings by Sol–Gel Method for Clinical Applications - Biological and Biomedical Coatings: Processing and Characterization - page 72

Conclusion
Both thick and thin nanocoatings offer the opportunity to modify the surface properties
of surgical-grade materials to achieve improvements in biocompatibility, reliability, and
performance. In recent years, the use of hydroxyapatite as coatings for drug-delivery sys-
tems and medical devices has gone through a transformation from being a rarity to being
an absolute necessity. Sol-gel derived coatings demonstrate significant promise in clinical
applications due to their relative ease of production and the ability to form a chemically
and physically uniform and pure coating over complex geometric shapes. Sol-gel derived
coatings also have the potential to deliver exceptional mechanical properties owing to
their nanocrystalline structure.
Currently used micro- and macrohydroxyapatite coatings on titanium alloys and cobalt
chromium alloy implants have had nearly 20 years of clinical use, and their success rate has
been controversial and in some instances negative. The equipment used is expensive and
control of the production factors is cumbersome. The work on sol-gel derived nanocrystal-
line hydroxyapatite both in vitro and in vivo studies are very promising and their applica-
tion at tissue-implant interfaces on knee, hip, and dental implants due to their bioactivity
can be advantageous and can help to improve reliability and longevity of the implants.
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