Although it has been generally accepted that calcium orthophosphate coatings, layers and films improve bone strength and initial osteointegration rate, the optimal coating properties required to achieve maximal bone response are yet to be reported.
Studies revealed alterations in the chemical composition of the ion beam deposited coatings, layers or films.
Unfortunately, due to densification during sintering, shrinkage and cracking of the coatings, layers or films can occur.
As-formed coatings, layers or films are porous, less dense and have poor adhesion to the substrate.
The resulting coatings, layers or films consist of a number of calcium orthophosphate phases plus various random admixtures.
In this approach, firstly thin (a few hundred atomic layers thick) and amorphous calcium orthophosphate coatings, layers or films are usually deposited.
To conclude this section, one should note that the positive clinical benefits of calcium orthophosphate coatings, layers and films were not always detected.
For all types of thermal spraying techniques, the quality of coatings, layers and films is generally increased with increasing particle velocities (Fauchais et al. 2001).
Since biomimetic deposition of calcium orthophosphate coatings, layers or films is a slow process, ways were sought to make it faster.
The deposited coatings, layers and films frequently consist of several calcium orthophosphates (often with admixtures of other substances, such as CaO, calcium pyrophosphates, etc).
