Objective. The present study aimed to investigate the effect of fluoride-modified titanium surface on adhesion of irradiated osteoblasts. Materials and Methods. Fluoride-modified surface was obtained and the morphology, roughness, and chemical composition of the surface were evaluated by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. The adhesion of irradiated osteoblast-like cells, in terms of number, area, and fluorescence intensity on the titanium surface, was evaluated using immunofluorescence staining. Results. Numerous nanosize pits were seen only in the F-TiO surface. The pits were more remarkable and uniform on F-TiO surface than on TiO surface; however, the amplitude of peaks and bottoms on F-TiO surface appeared to be smaller than on TiO surface. The Sa value and Sdr percentage of TiO surfaces were significantly higher than those of F-TiO surface. The concentrations of main elements such as titanium, oxygen, and carbon were similar on both surfaces. The number of irradiated osteoblasts adhered on the control surface was larger than on fluoride-modified surface. Meanwhile, the cells on the fluoride-modified surface formed more actin filaments. Conclusions. The fluoride-modified titanium surface alters the adhesion of irradiated osteoblasts. Further studies are needed to investigate the proliferation, differentiation, maturation, gene expression, and cytokine production of irradiated osteoblasts on fluoride-modified titanium surface
