Composition of solutions and parameters of the processes used in the application of biomimetic coatings on titanium. State of the art

Abstract

In recent years, many researchers have focused their attention on processes that occur in living organisms
because it is possible to reproduce in vitro. Based on this behavior, Tadashi Kokubo and colleagues developed a method
for obtaining apatite coatings on bioactive surfaces from the immersion of the samples to be coated in a simulated body
fluid. An update on the state of the art of this topic, emphasizing the composition of solutions and process parameters
used during the treatment of titanium and their alloys is presented. As a result of the study it was possible to confirm that
there is a tendency to increase the content of calcium and phosphate ions in solutions to accelerate of formation and
subsequent growth of the coating. The use of these ion concentrations at levels that exceed 10 times as much as those
presented by the simulated body fluid was reported. The inclusion of magnesium and hydrogen carbonate salts carriers
and sodium chloride in the solutions can also affect positively the deposition speed of the coating and at the same time
they can affect the crystallinity of the resulting apatite structures. High levels of hydrogen carbonate and magnesium
ions in solutions generate amorphous structures in coatings. The parameters pH and temperature also have a significant
influence on the deposition process helping to control the velocity of deposition process.