Effect of fluoride-modified titanium surface on irradiated osteoblast adhesion

Abstract

Objectives: To investigate the effect of fluoride-modified titanium surface on early adhesion of irradiated osteoblasts. Methods: Human osteoblast-like cell lines (SaOS-2) in density of 2×104cell/mL were radiated. Cells received a single dose of 0Gy, 2Gy, 4Gy, 6Gy, 8Gy, 10Gy radiation respectively using a 10 MV photon. After irradiation, 40µl cell suspension was seeded onto either titanium dioxide blasted discs with (test group) or without (control group) fluoride-modified surface treatment respectively. The discs were then cultured under standard conditions for 24 hours. Cell number was assessed by DAPI staining and fluorescence microscope observation; cytoskeletal changes were analyzed using phalloidine for f-actin staining and cell area was measured using fluorescence microscope. The mean values between the two groups were compared by independent t-test and differences among different radiation doses were compared by one-way ANOVA. Differences were considered significant at P < .05.

Results: There was a significant reduction in the mean number of osteoblasts with increasing irradiation dosage in both groups. The mean number of osteoblasts in test group was significantly less than the control group at 8Gy and 10Gy. There was a significant increase in the mean cell area with increasing irradiation dosage in the control group while in the test group, the mean cell area of osteoblasts at 2Gy and 4Gy was significantly less than other dosages. The mean cell area of osteoblasts in the control group was significantly larger than the test group at 4Gy and 6Gy.

Conclusions: This in vitro study showed that irradiation compromised the early cell adhesion of osteoblasts to titanium discs. The fluoride surface treatment on titanium discs affects the behaviour of irradiated osteoblasts and that might partly be due to the more hydrophobic surface with increased roughness.