Tribological behaviour of orthodontic archwires under dry and wet sliding conditions in-vitro. II--Wear patterns.
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.
Berradja
Abdenacer
A
Department of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Leuven, Belgium.
Willems
Guy
G
Celis
Jean-Pierre
JP
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
D003722:Dental Alloys; D014867:Water; C040654:titanium nickelide; D013193:Stainless Steel; D012965:Sodium Chloride; D009532:Nickel; D014025:Titanium; D000537:Aluminum Oxide