CHARACTERIZATION OF BIOMIMETIC HYDROXYAPATITE COATINGS ON SS316L

Hydorxyapatite coatings on 316l SS were prepared with the objective of improving the osseointegration processes between implants and tissue by a biomimetic method. This method consists in the immersion of SS316L samples in a simulated body fluid solution (SBF) that imitates the inorganic ionic concentration of blood plasma during different periods to form hydroxyapatite. The effect of superficial roughness, alkaline treatment, oxidation and calcium concentration in the SBF solution was evaluated by the analysis of the coating by AFM and SEM. Two groups of samples were employed: one with specular finishing and the other with a surface roughness of 600 grit. Both groups of samples were treated with NaOH, 5M during 24h at75(0)C. One of the groups was oxidized at 400 (0)C, 1h. The samples were inmersed in two SBF solutions, one conventional and the other calcium saturated (SBF-SC) for 8 weeks. AFM showed a dense coating forming oval clusters in the samples treated in SBF-SC. This morphology pattern was also observed in the other condition in the early stage of formation.