Abstract:
In this work, electrodeposition of hydroxyapatite on commercially pure titanium was attempted to
promote bone in-growth. Coatings were electrodeposited in mixed solution of Ca(N03)2 4H2O and
NH4H2PO4 with constant current density of 10 mA/cm the power of 2. The effects of deposition temperature and
time on morphology, crystal structure and biocompatibility of coatings were studied. Indicated by
XRD technique, coatings formed at temperature of 30 and 40 ํC were composed of brushite and
hydroxyapatite, whereas those obtained at temperature of 50 and 60 ํC only hydroxyapatite was
detected. Deposition time did not show any effect on crystal structure of coating. SEM-EDX
investigation revealed that plate shape morphology represented brushite structure; while, flake and
nodular morphologies corresponded to hydroxyapatite structure. Transformation of brushite to
hydroxyapatite could be achieved by soaking in 1 M NaOH at 30 ํC for 2 hours. Crystallite sizes of
hydroxyapatite produced from this work were 16 - 41 nm which were similar to those found in
human bone.Hydroxyapatite coatings formed through either direct electrodeposition or
transformation in NaOH were non-toxic. However, the directly-formed hydroxyapatite promoted
newly formed hydroxyapatite in Simulated body fluid (SBF) and responded to Osteoblast cell in
terms of amount of cell growth and cell adhesion better than hydroxyapatite obtained by
transformation.