A new combined approach to metal-ceramic implants with controllable surface topography, chemistry, blind porosity, and wettability

The present work focuses on the surface modification of Ti alloys using a combination of various techniques such as cold spray (CS), selective laser sintering (SLS), pulsed electro-erosion treatment (PEET), and magnetron sputtering to control surfacetopography (roughness and blindporosity), surfacechemistry, and wettability, i.e. the characteristics which affect osseointegration. The sample structure, elemental composition, surfacetopography, and wettability were studied using X-ray diffraction, optical and scanning electron microscopy, glow discharge optical emission spectroscopy, energy dispersive spectroscopy, and water contact angle measurements. The obtained results show that Ti coatings deposited by CS can be divided into three groups with a characteristic value of average roughness Ra: (i) 4 µm (single particles and agglomerates on the surface), (ii) 22 µm (thin coatings), and (iii) 80 µm (thick coatings). PEET with pulse discharge energies of 0.025 and 0.38 J resulted in the average values of surface roughness of 3 and 8 µm, respectively. During SLS, Ti powder paths were sintered by a laser beam in mutually perpendicular directions to form surface network structures. By varying the distance between the tracks, samples with blindporosity 1.0–5.1 × 10- 3 mm3 were obtained. In order to modify the surfacechemistry, multifunctional bioactive nanostructured TiCaPCON films, 1–2 µm thick, were deposited atop the CS, PEET, and SLS samples by sputtering a composite TiC0.5 + Ca3(PO4)2 target. The wettability measurements showed that the CS and PEET modified surfaces exhibit high values of water contact angle. Ion etching in vacuum and TiCaPCON film deposition made the samples highly hydrophilic. The influence of the surfacechemistry and surfacetopography on adhesion, proliferation, and early stages of osteoblasts differentiation was studied. The combination of high surface roughness and blindporosity with hydrophilicity and biocompatibility makes the fabricated metal-ceramic materials promising candidates for applications involving tissue regeneration.