title: Sterilization of heat-sensitive silicone implant material by low-pressure gas plasma.
abstract: BACKGROUND
  In recent years, plasma treatment of medical devices and implant materials has gained more and more acceptance. Inactivation of microorganisms by exposure to ultraviolet (UV) radiation produced by plasma discharges and sterilization of medical implants and instruments is one possible application of this technique. The aim of this study was to evaluate the effectiveness of this sterilization technique on silicone implant material.
  
  
  METHODS
  Bacillus atrophaeus spores (10(6) colony-forming units [CFUs]) were sprayed on the surfaces of 12 silicone implant material samples. Four plasma sets with different gas mixtures (argon [Ar], argon-oxygen [Ar:O(2)], argon-hydrogen [Ar:H(2)] and argon-nitrogen [Ar:N(2)]) were tested for their antimicrobial properties. Post-sterilization mechanical testing of the implant material was performed in order to evaluate possible plasma-induced structural damage.
  
  
  RESULTS
  The inductively coupled low-pressure plasma technique can achieve fast and efficient sterilization of silicone implant material without adverse materials effects. All four gas mixtures led to a significant spore reduction, and no structural damage to the implant material could be observed.
authors.affiliation: Department of Plastic Surgery, Bergmannsheil University Hospital, Bochum, Germany. joerg.hauser@rub.de
authors.forename: Joerg
authors.initials: J
authors.lastname: Hauser
authors.forename: Stefan-Alexander
authors.initials: SA
authors.lastname: Esenwein
authors.forename: Peter
authors.initials: P
authors.lastname: Awakowicz
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Steinau
authors.forename: Manfred
authors.initials: M
authors.lastname: Köller
authors.forename: Helmut
authors.initials: H
authors.lastname: Halfmann
mesh_terms: D001128:Argon; D001407:Bacillus / Q000187:drug effects; D015169:Colony Count, Microbial; D006859:Hydrogen; D009584:Nitrogen; D010100:Oxygen; D058626:Plasma Gases; D011312:Pressure; D019736:Prostheses and Implants / Q000382:microbiology*; D012828:Silicones; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development; D013242:Sterilization / Q000379:methods*
chemical_list: D058626:Plasma Gases; D012828:Silicones; D001128:Argon; D006859:Hydrogen; D009584:Nitrogen; D010100:Oxygen