Introduction: Titanium surface modifications can influence the osseointegration process, the final goal being accelerate bone formation around implants.

Purpose: This study aimed at evaluating the effect of Ti surface modification by nitriding on osteoblastic cell adhesion and spreading.

Material and methods: Plasma nitriding treatments were carried out in Ti discs using atmosphere with 20% N ₂ and 80% H ₂ at 450 °C and 3 different conditions of pressure and time (Group 1: 1.5 mbar for 1 h; Group 2: 2.6 mbar for 1 h; Group3: 2.6 mbar for 3 h). Untreated discs were used as control. Osteoblastic cells derived from human alveolar bone were cultured on Ti discs for 2 h, fixed and stained with phalloidin (cytoskeleton) and DAPI (nuclei). Under fluorescence microscopy, cell adhesion was evaluated by counting the number of cells in 10 fields under 20× of magnification and cell spreading was evaluated by measuring the area of 40 cells, for each Ti surface. Data were compared by ANOVA means followed by Tuckey test ( p < 0.05).

Results: Both cell adhesion and spreading were significantly lower in Group 3 while Groups 1 and 2 displayed values similar to control.

Conclusion: These results suggest that nitriding under higher pressure for periods longer than 1 hour produces Ti surfaces that disturb the earlier osteoblastic cell behaviors such as adhesion and spreading.

Financial support: FAPESP and CNPq .

Conflict of interest: None declared.