Osteoblast Attachment Compromised by High and Low Temperature of Titanium and Its Restoration by UV Photofunctionalization

Titanium implants undergo temperature fluctuations during manufacturing, transport, and storage. However, it is unknown how this affects their bioactivity. Herein, we explored how storage (six months, dark conditions) and temperature fluctuations (5-50 degrees C) affected the bioactivity of titanium implants. Stored and fresh acid-etched titanium disks were exposed to different temperatures for 30 min under wet or dry conditions, and their hydrophilicity/hydrophobicity and bioactivity (using osteoblasts derived from rat bone marrow) were evaluated. Ultraviolet (UV) treatment was evaluated as a method of restoring the bioactivity. The fresh samples were superhydrophilic after holding at 5 or 25 degrees C under wet or dry conditions, and hydrophilic after holding at 50 degrees C. In contrast, all the stored samples were hydrophobic. For both fresh and stored samples, exposure to 5 or 50 degrees C reduced osteoblast attachment compared to holding at 25 degrees C under both wet and dry conditions. Regression analysis indicated that holding at 31 degrees C would maximize cell attachment (p < 0.05). After UV treatment, cell attachment was the same or better than that before temperature fluctuations. Overall, titanium surfaces may have lower bioactivity when the temperature fluctuates by >= 20 degrees C (particularly toward lower temperatures), independent of the hydrophilicity/hydrophobicity. UV treatment was effective in restoring the temperature-compromised bioactivity.

Automated summary

The study investigated the impact of storage and temperature fluctuations on the bioactivity of titanium implants. It was found that stored samples were more hydrophobic compared to fresh samples, which significantly affected osteoblast attachment. Maintaining the samples at 31 degrees Celsius was shown to maximize cell attachment. UV treatment was effective in restoring bioactivity compromised by temperature fluctuations.