Effect of surface roughness of ground titanium on initial cell adhesion

The effect of surface roughness of ground Ti on the initial adhesion of osteoblast-like U-2 OS cells was investigated in this study. Different numbers (#120, #600, and #1500) of SiC sandpaper and two Al2O3 polishing powder (0.3 and 1 mum) were used to prepare the metal specimens with varying degrees of surface roughness. Surface roughness (R-a) was measured by profilometry. Surface topography was observed using an atomic force microscope. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was used to measure the optical density (OD) of specimens after 2 h of cell incubation. The OD value was analyzed by one-way ANOVA for analyzing the factor of surface roughness. Crystal violet staining technique was used to characterize the cell spreading. Results showed that the specimen of #1500 Ti (R-a: 0.15 mum) had the highest OD value. The specimens polished with 0.3 and 1 mum Al2O3 powder (R-a: 0.05 and 0.07 mum) exhibited the worst cell adhesion behavior. Contact guidance of cells could be observed on the rougher #600 and #120 specimens (R-a: 0.33 and 1.20 mum). This study concludes that the surface roughness (R-a: 0.05-1.20 mum) of ground Ti has a highly significant influence on the initial adhesion of osteoblast-like U-2 OS cells. The ground Ti with an R-a of 0.15 mum shows the optimal cell adhesion behavior with respect to either the rougher or smoother specimens. (C) 2004 Elsevier B.V. All rights reserved.