Purpose: The aim of this study was to generate periodic microstructures on pure titanium surface by femtosecond laser-etching after sandblasting, and to assess the physicochemical properties of its surface.
Methods: Twelve pure titanium discs with diameter of 10 mm and thickness of 4 mm were used and divided into 3 groups according to different surface treatment methods: group S (sandblasting surface), group SA (sandblasting surface with acid-etching), and group SL (sandblasting surface with femtosecond laser-etching). Scanning electron microscopy (SEM) was used to observe the surface morphology. X-ray energy spectrum(EDS) was used to observe the surface chemical compositions. Three dimensional surface topography and surface roughness were evaluated by laser scanning confocal microscope (CLSM). The static contact angle was detected by high temperature wetting angle measuring instrument. SPSS19.0 software package was used for statistical analysis.
Results: SEM and CLSM showed well-distributed periodic and cyclic microstructure which formed second-order roughness composite structure in group SL. EDS analysis showed that the Al element on SL surface decreased (group SL 4.37%<group S 5.18%<group SA 7.27%), and the ratio of O/Ti increased (group SL 1.74>group SA 0.32>group S 0). Surface roughness analysis showed that surface roughness significantly increased in group SL [group SL (7.33±0.38)μm>group SA (1.08±0.12)μm>group S (1.05±0.14)μm](P<0.001). Static contact angle analysis showed that the static contact angle of surface was significantly reduced in group SL [group SL (34.4±2.5)°<group SA (65.0±2.9)°<group S (83.7±2.6)°] (P<0.001).
Conclusions: Sandblasting combined with femtosecond laser-etching of pure titanium surface has excellent surface physicochemical properties and is a promising surface modification technology for titanium implant.