Electrolytic coating of calcium phosphate on titanium: Optimisation of the conversion of monetite to hydroxyapatite

Electrolytic deposition has been proposed as an alternative method of coating hydroxyapatite on metallic substrates. The aim of this study was to characterise the conversion process in order to determine the minimum time to complete the monetite to hydroxyapatite transformation. Titanium substrate coated with monetite by electrolytic deposition was treated with NaOH solution in different time points. XRD spectra indicated that a reaction time of four hours was enough to convert all monetite to hydroxyapatite. Carbonate in B and A sites of hydroxyapatite were identified by IR using the diffuse reflectance mode (DR-IR). However, DRX-IR analysis of the converted sample indicated that the resulting coating consists of hydroxyapatite with low carbonate content.