Among all biomaterials used for bone replacement,
it is recognized that both commercially pure titanium (Ti c.p.)
and Ti6Al4V alloy are the materials that show the best in vivo
performance due to their excellent balance between
mechanical, physical-chemical and biofunctional properties.
However, one of its main drawbacks, which compromise the
service reliability of the implants and its osteointegration
capacity, is the thin film of fibrous tissue around the implant
due to the bioinert behaviour of titanium. One of the
alternatives more studied to improve the titanium
osteointegration is the surface modification through the
control of the roughness parameters within a specific range
which is recognized that improve the osteoblasts adhesion. In
this work is investigated the influence of different
electrochemical processing conditions for surface modification
of c.p. Ti, in their microstructural, morphological,
topographical and mechanical properties, as well as in their
biological behaviour. The electrochemical anodizing treatment
was performed by using different electrolytes based on
phosphoric acid (H3PO4), sulphuric acid (H2SO4) with a
fluoride salt; and the Focused Ion Beam (FIB) technique,
normally named as Nanolab, was used for the microstructural,
chemical and morphological characterization, as well as the
confocal laser microscopy technique which also served for
roughness measurements. The mechanical response of the
anodic layers was evaluated through the using of a scratch
tester which showed the critical loads for the coating damages.
The characterization results showed that both, concentrations
and electrolyte species, clearly influenced the morphological
and topographical features, as well as the chemical
composition of the anodic layer. By using the FIB was possible
to detect nanopores within both the surface and the bulk of the
coating. Some of the conditions generated a very special
coating morphology which promoted a better osteoblasts
adhesion. Contrary to what it was a priory expected, all anodic
coatings showed high critical loads for damages during scratch
test, despite their high porosity, which could be related with
some defects coalescence mechanism that allows dissipating the
high stress concentration applied during the test.
