title: Corrosion of orthodontic pliers using different sterilization procedures.
abstract: OBJECTIVE
  The aim of this study was to investigate the corrosion resistance of orthodontic pliers from several manufacturers following different sterilization procedures, namely heat sterilization and the use of a disinfectant agent (Sekusept Extra N in an ultrasonic bath.
  
  
  METHODS
  Employed in this study were ten distal-end cutters and ten Weingart pliers manufactured by Aesculap, ETM and Hu-Friedy, examined under electron microscopy for evidence of corrosion following 500 sterilization cycles. The corrosion data were recorded photographically and graphically. Metallographic microsections were prepared from each pair of pliers and were then analyzed by means of EDX measurements to assess the chemical alloy composition.
  
  
  RESULTS
  The light and electron microscopic evaluation showed that both heat sterilization and high level disinfection caused corrosive changes on the pliers. However, the type of corrosion differed between the two sterilization methods. The main type of corrosion with Sekusept Extra N was pitting, while with heat sterilization it was surface corrosion. Heat sterilization was the type of corrosion that caused the most corrosive changes, regardless of which type of corrosion was considered. However, these results must be viewed critically, because pitting corrosion is obviously a more severe problem than surface corrosion. In comparing the pliers of various manufacturers, differences were noted. However, it was difficult to rank them when the correct maintenance regime was adhered to. The soldered joint gap was revealed to be a specific weak point, and that area proved to be inadequate due to qualities related to their production, particularly in the Hu-Friedy pliers.
  
  
  CONCLUSIONS
  This study showed that heat sterilization leads to less corrosion than cold disinfection. Corroded pliers can be restored to a useable condition by re-polishing, though it is important that the instructions for their care be strictly adhered to.
authors.affiliation: Department of Orthodontics and Paediatric Dentistry, University of Basle, Switzerland. Andrea.Wichelhaus@unibas.ch
authors.forename: Andrea
authors.initials: A
authors.lastname: Wichelhaus
authors.forename: Gert
authors.initials: G
authors.lastname: Brauchle
authors.forename: Matthias
authors.initials: M
authors.lastname: Mertmann
authors.forename: Franz Günter
authors.initials: FG
authors.lastname: Sander
mesh_terms: D003343:Corrosion; D003762:Dental Instruments; D004202:Disinfectants; D004868:Equipment Failure; D019544:Equipment Failure Analysis; D006358:Hot Temperature; D019552:Infection Control, Dental / Q000379:methods*; D008422:Materials Testing; D009970:Orthodontics / Q000295:instrumentation*; D013010:Sonication; D013193:Stainless Steel / Q000032:analysis / Q000737:chemistry*; D013242:Sterilization / Q000379:methods*; D013499:Surface Properties
chemical_list: D004202:Disinfectants; D013193:Stainless Steel