Evaluation of Degradability of CaTiO3 Thin Films in Simulated Body Fluids

In vitro dissolution behaviors of CaTiO3 thin films deposited with ion beam assisted deposition (IBAD) and sputter-deposition techniques were investigated using Rutherford backscattering spectrometry (RBS) and Auger electron spectroscopy (AES). In vitro test was carried out by immersion in a simulated body fluid at 37 C for 5, 24, and 888 h. The dissolution of titanium ions from CaTiO3 film was almost independent of deposition techniques while that of calcium ions was dependent on those. In the specimens deposited by sputter-deposition, the dissolution rate of the calcium ions increased proportionally with time, and in the case of IBAD, it increased proportionally with the logarithm of time. Furthermore, in IBAD, the dissolution rate of the calcium ions was also intimately related with the total kinetic energy of the titanium ions when implanted. The results reveal that IBAD CaTiO3 coating film makes it possible to control dissolution rate of calcium ions from the film.