Thesis (M.Sc.)--Chulalongkorn University, 2011

Blasting titanium with abrasive particle is the method used to generate surface topography and roughness to improve cellular responses. The behavior of MC3T3-E1 cells was compared on six different titanium surfaces: polished titanium (Ti-polish), titanium blasted with glass beads (SiO₂) particles of 50 or 100 µm in size (50SiO₂-Ti, 100SiO₂-Ti) and titanium blasted with Al₂O₃ particles of 50,100 or 250 µm in size (50Al₂O₃-Ti, 100Al₂O₃-Ti, 250Al₂O₃-Ti). Profilometry showed the comparable roughness values for the surface blasted with the same size particle, (Sa= 0.5340, 0.5288 µm for 50SiO₂-Ti and 50Al₂O₃-Ti) (Sa=0.6323, 0.6343 µm for 100SiO₂-Ti and 100Al₂O₃-Ti). While the 250Al₂O₃-Ti had the highest roughness values (Sa= 1.5168 µm). Both the SiO₂ and Al₂O₃ blasted surfaces were hydrophilic materials but only Al₂O₃ blasted surface could support higher amount of fibrin formation after 5 minutes. In addition, cells seeded on 250Al₂O₃ –Ti showed faster rate of adhesion at 30 min, higher rate of proliferation at day 2, higher expression of collagen type I and osteocalcin at day 7 than the other surfaces. Moreover, increased expression of osteocalcin at day 14 and more alizarin red-S staining at day 14 were observed on Al₂O₃ blasted surfaces compared to the SiO₂ blasted surfaces. However, no significant differences in cell response among the groups, which prepared by different size of Al₂O₃ were detected. The results of this study indicated that Al₂O₃ blasted surface could support the osteoblast adhesion, differentiation and mineralization better than SiO₂.These results suggested that the 250Al₂O₃ –Ti supported the greatest initial adhesion, proliferation and initial gene expression of MC3T3-E1 cells.