title: Tribological behaviour of orthodontic archwires under dry and wet sliding conditions in-vitro. II--Wear patterns.
abstract: OBJECTIVE
  To evaluate the wear patterns of orthodontic archwires in dry and wet conditions in-vitro.
  
  
  METHODS
  The patterns of wear of stainless steel and NiTi orthodontic archwires were investigated with a fretting wear tribometer fitted with an alumina ball. The tribometer was operated at 23 degrees C in three different environments: ambient air with 50 per cent relative humidity (RH), 0.9 wt. per cent sodium chloride solution and deionised water. Differences in the wear characteristics of the archwires were investigated by scanning electron microscopy. Energy Dispersive X-ray Analysis and Inductively Coupled Plasma Analysis were used to investigate the surface composition of the wires, the wear debris generated during fretting and the corrosion products in the test solutions.
  
  
  RESULTS
  Both archwire materials were degraded by oxidational wear in ambient air. The NiTi wires were more resistant to wear than the stainless steel wires. In the aqueous media the stainless steel wires were degraded by abrasive wear, while the NiTi wires were degraded by adhesive wear.
  
  
  CONCLUSIONS
  In ambient air with 50 per cent RH, NiTi wires were more resistant to wear than stainless steel wires. Both archwire materials exhibited higher wear rates in the solutions than in air, indicating some synergism between the wear and corrosion processes. In the solutions the stainless steel archwires had a much lower corrosion-wear resistance than the NiTi archwires.
authors.affiliation: Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Abdenacer
authors.initials: A
authors.lastname: Berradja
authors.forename: Guy
authors.initials: G
authors.lastname: Willems
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Celis
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D003890:Desiccation; D004577:Electron Probe Microanalysis; D017276:Friction; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D010084:Oxidation-Reduction; D012965:Sodium Chloride / Q000737:chemistry; D013054:Spectrophotometry, Atomic; D013193:Stainless Steel / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D003722:Dental Alloys; D014867:Water; C040654:titanium nickelide; D013193:Stainless Steel; D012965:Sodium Chloride; D009532:Nickel; D014025:Titanium; D000537:Aluminum Oxide