title: Effect of different sterilization modes on the surface morphology, ion release, and bone reaction of retrieved micro-implants.
abstract: OBJECTIVE
  To compare as-received and sterilized micro-implants in order to assess the prospects of reusing them.
  
  
  METHODS
  Forty micro-implants from a single manufacturing lot were used in the study. Thirty were retrieved from patients after successful service in their mouth and with no signs of failure. The retrieved micro-implants were divided into three groups, according to method of sterilization: autoclave, gamma radiation, or ultraviolet radiation. All groups were subjected to scanning electron microscope analysis for surface morphology assessment. The specimens were immersed in a standard simulated body-fluid solution kept at 37°C in an incubator; the solution was then withdrawn at 24 hours and 30 days to evaluate aluminum and vanadium ion release by atomic absorption spectrophotometer in parts per billion. The micro-implants were then surgically implanted into the tibia of rabbits for a 1-month healing period, and the bone-implant blocks were processed for routine histologic examination.
  
  
  RESULTS
  This study revealed that sterilized micro-implants had altered surface topography, different ion release values, and different histologic cell reactions than the as-received micro-implants.
  
  
  CONCLUSIONS
  Within the limitations of this study, it can be concluded that retrieved self-drilling micro-implants have tip sharpness variations that require correction before insertion by bone drilling. The autoclave-sterilized micro-implants showed better histologic results than micro-implants sterilized by gamma or ultraviolet rays.
authors.affiliation: a  Assistant Professor of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
authors.forename: Noha
authors.initials: N
authors.lastname: El-Wassefy
authors.forename: Abeer
authors.initials: A
authors.lastname: El-Fallal
authors.forename: Mahasen
authors.initials: M
authors.lastname: Taha
mesh_terms: D000497:Alloys; D000535:Aluminum / Q000032:analysis; D000818:Animals; D000069343:Bone-Implant Interface / Q000473:pathology; D003722:Dental Alloys / Q000737:chemistry; D015921:Dental Implants; D004577:Electron Probe Microanalysis; D017743:Equipment Reuse; D005720:Gamma Rays; D006358:Hot Temperature; D007101:Immersion; D008855:Microscopy, Electron, Scanning; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D011817:Rabbits; D013054:Spectrophotometry, Atomic; D013242:Sterilization / Q000295:instrumentation / Q000379:methods*; D013499:Surface Properties; D013696:Temperature; D013977:Tibia / Q000473:pathology*; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D014639:Vanadium / Q000032:analysis
chemical_list: D000497:Alloys; D003722:Dental Alloys; D015921:Dental Implants; D014639:Vanadium; C031462:titanium alloy (TiAl6V4); D000535:Aluminum; D014025:Titanium
keywords: Bone interface histology; Ion release; Micro-implants; Sterilizations; Surface morphology