title: Effect of argon protection on the biological activity of acid etched titanium surface.
abstract: OBJECTIVE
  As the contamination of implant surface seriously affects the early osseointegration of implants and reduces the survival rate of implants, it has attracted wide attention of researchers. The most oral titanium implants used in current clinical applications are stored in sealed packages. During the process of packaging, storage and usage, the implants inevitably contact air, which results in the surface contamination. As an inert gas, the argon has very inactive chemical properties and is routinely used as a protective gas to cut air pollution. In this study, we investigated whether argon protection can cut air pollution and maintain lasting surface biological activity of titanium implants.
  
  
  METHODS
  We prepared sandblasting etched titanium samples under air protection or under argon protection. The samples prepared under air protection were used as the control. With the scanning electron microscopy, the contact angle measurements and the X-ray photoelectron spectroscopy, we examined surface morphology, hydrophilicity, chemical structures and components of the implants prepared under two gas protections. By using beagles as the animal model, we assessed the bone guide of the implants prepared under argon protection and morphological changes of surrounding tissues.
  
  
  RESULTS
  While compared with those implants prepared under air protection, the surface morphology of implants prepared under argon protection did not change, which had preferable hydrophilicity, and there were differences in percentage of surface chemical elements and chemical structure. After 4 weeks, the bone-implant contact (BIC) in argon protection group was twice of the control group and the difference was statistically significant (p < 0.01). The Implant Niuchu experiments also proved that under argon protection, the implants would have good integration with the surrounding bone tissues.
  
  
  CONCLUSIONS
  This study revealed the implants prepared under argon can cut air pollution and have high bone guide property and biological activity.
authors.affiliation: Guangdong Provincial Stomatological Hospital, Southern Medical University, Haizhu District, Guangzhou, China. zho668@263.net.
authors.forename: Y-D
authors.initials: YD
authors.lastname: Zhao
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: J
authors.initials: J
authors.lastname: Yue
authors.forename: X-L
authors.initials: XL
authors.lastname: Ding
authors.forename: Y
authors.initials: Y
authors.lastname: Deng
authors.forename: B
authors.initials: B
authors.lastname: Du
authors.forename: L
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000393:Air Pollutants / Q000032:analysis; D000818:Animals; D001128:Argon / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry; D000069343:Bone-Implant Interface; D004285:Dogs; D008297:Male; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration; D019736:Prostheses and Implants; D013499:Surface Properties; D013977:Tibia; D014025:Titanium / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D001672:Biocompatible Materials; D001128:Argon; D014025:Titanium