Abstract
The initial adhesion of cells to the implant surface and the subsequent behavior of the cells are important for their biocompatibility. This study investigated the continuousness of the effects of glow-discharge (GD) treatment on the adhesion of cells to titanium.
Polished titanium plates (30 mm in diameter, 2 mm in thickness) were treated with GD. Human gingival fibroblast (hGF) cells were seeded on each treated sample. After 6 h of culture, cells were fixed and stained with TRITC-phalloidin to count the number of attached cells. After 24 h of culture, the cells were fixed and incubated with antibody against vinculin to examine the formation of focal adhesion. Titanium disks were treated using GD in a plasma chamber for 20-240 s. To compare with the effects of ultraviolet (UV) treatment, the titanium disks were exposed to UV for 6-48 h. Untreated titanium disks were used as controls (CON) . The hydrophilic status of the titanium surfaces was analyzed by XPS analysis, and the wettability was examined by the spread of 5 μL of H2O. Titanium disks treated with GD were in the air for 0-6 h after the treatment to examine the continuousness of the effects of GD treatment. The maximum wettability was observed by GD treatment for 120 s, whereas the maximum wettability by UV treatment was observed by the 48 h of UV treatment. The effect of GD decreased by half at 1 h after GD treatment and converged with the CON level at 6 h. The number of hGF cells attached to GD and UV after 6 h of incubation was significantly greater than that attached to CON. The number of vinculin immuno-positive focal adhesion per cell was significantly greater on GD and UV treated disks than on CON disks. Neither the number of attached cells nor focal adhesion formation showed significant differences between GD and UV.
These findings demonstrated that only 2 min of GD treatment on the titanium surfaces caused similar wettability and cell attachment as 48 h of UV treatment. However, the effect of GD treatment disappeared within 6 h in the air. The present study suggests that GD treatment is quite easy but titanium implants treated with GD should be used as soon as possible after GD treatment.
