Reduction effect of nickel ion release on a diamond-like carbon film coated onto an orthodontic archwire

• Published in: Thin solid films 2006-02, Vol.497 (1-2), p.218-222
• Main Authors: Ohgoe, Yasuharu, Kobayashi, Shinya, Ozeki, Kazuhide, Aoki, Hideki, Nakamori, Hideki, Hirakuri, Kenji K., Miyashita, Osamu
• Format: Article
• Language: English
• Subjects: Cell culture; Cross-disciplinary physics: materials science; rheology; DLC film coatings; Exact sciences and technology; Ion and electron beam-assisted deposition; ion plating; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nickel ion release; Nickel–titanium alloy orthodontic archwires; Physics
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2005.11.003

Diamond-like carbon (DLC) film has been coated onto nickel–titanium alloy orthodontic archwires using an arc discharge ion plating process to prevent corrosion and nickel ion release from the orthodontic archwires. Nickel ion release was observed in the immersion test in physiological saline at 85 °C for 5 days. The amount of the nickel ion release was measured by using microwave-induced plasma mass spectroscopy, and for the DLC film-coated samples, the nickel ion release level was 50 ppb. The DLC film coating reduced the nickel ion release level by 80%. Additionally, human adult gingival fibroblasts were used in a cell culture to investigate the effect of nickel ion release on cell growth. As a result, the DLC film coating suppressed the influence of the nickel ion release to the cell culture. DLC films are suitable for circumventing the problem of nickel ion release from nickel–titanium alloy orthodontic archwires.