Mg substituted apatite coating from alkali conversion of acidic calcium phosphate

•The presence of Mg ions influenced the final apatite phase present in the produced coatings.•A lower efficiency in heterogeneous deposition and an exposure of Ti substrate in 5% Mg-monetite coatings was soon verified.•McCoy culture medium was effective in predicting the coatings bioactivity.

In this work, two solutions were developed: the first, rich in Ca2 +, PO43 − ions and the second, rich in Ca2 +, PO43 − and Mg2 +, defined as Mg-modified precursor solution. For each Mg-modified precursor solution, the concentrations of Mg2 + ions were progressively increased by 5%, 10% and 15%wt. The aims of this research were to investigate the influence of magnesium ions substitution in calcium phosphate coatings on titanium surface and to evaluate these coatings by bioactivity assay in McCoy culture medium. The obtained coatings were characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis, and the presence of Mg ions was confirmed by the inductively coupled plasma atomic emission spectroscopy (ICP) analysis. In vitro bioactivity assay in McCoy culture medium showed bioactivity after 14 days in incubation for the HA and 10% Mg-monetite coatings. The high chemical stability of Mg-HA coatings was verified by the bioactivity assays, and no bone-like apatite deposition, characteristic of bioactivity, was observed for Mg-HA coatings, for the time period used in this study.