Bioactive glass coatings: a review

Bioactive glasses, discovered by Hench and co-workers at the end of the 1960s, are among the most promising biomaterials for bone repair and reconstruction, mainly thanks to their high bioactivity index. Unfortunately, due to their brittleness and relatively poor mechanical properties, their clinical applications are limited to non-load bearing implants. However, bioactive glasses can be successfully employed as coatings on bioinert metallic substrates, in order to combine high bioactivity with mechanical strength. After a brief introduction to the main properties of biomaterials and bioactive glasses, the present paper provides an overview of the different approaches and available techniques to realise bioactive glass coatings, with a particular emphasis on thermal spray, which is nowadays one of the most popular coating procedures.