Table 1.

Examples of surface modification of Ti and Ti alloys.

Alloys	Method	Modified Layer Thickness	Aims	Refs.
CP Ti	Atmospheric thermal oxidation + micro-arc oxidation (MAO)	∼2 μm (with a ∼70 μm oxygen diffusion layer)	The modified layer reduced the corrosion rate, and improved the tribocorrosion resistance, biocompatibility, and bonding between cells.	[48]
Ti64	Plasma spray coating	∼150 μm	The coating decreased the release of metal ions and improved corrosion resistance and microhardness values.	[49]
Ti-4Al-7Nb	High-speed milling	60–150 μm	The modified surface reduced the surface Young’s modulus and improved the hardness, corrosion resistance, and biocompatibility.	[50]
Ti-15Mo	MAO (in baths containing zinc)	3–15 μm	The coating increased surface the bioactivity and cytocompatibility and slightly improved the bacteriostatic effect.	[51]
Ti2448	Sandblasting, dual acid-etching, and alkali thermal treatment	∼3 μm	The surface roughness increased, and the surface wettability improved	[52]
Ti–29Nb–13Ta–4.6Zr (TNTZ)	Ultrasonic nanocrystal surface modification	∼150 μm (within the top ∼30 μm, a large amount of plastic deformation)	The nanostructured surface layer increased the wear resistance and cell adhesion area.	[53]