Tribological behaviour of orthodontic archwires under dry and wet sliding conditions in-vitro. I--Frictional behaviour.
OBJECTIVE
To evaluate the frictional behaviour of orthodontic archwires in dry and wet conditions in-vitro.


METHODS
Two types of archwire materials were investigated: stainless steel and NiTi. A fretting wear tribometer fitted with an alumina ball was operated at 23 degrees C in three different environments: ambient air with 50 per cent relative humidity, 0.9 wt. per cent sodium chloride solution, and deionised water.


RESULTS
NiTi archwires sliding against alumina exhibited high coefficients of friction (about 0.6) in the three environments. Stainless steel archwires sliding against alumina had relatively low coefficients of friction (0.3) in the solutions, but high coefficients (0.8) in air.


CONCLUSIONS
The low frictional forces of the stainless steel wires sliding against alumina in the solutions were due to a lubricating effect of the solutions and corrosion-wear debris. The high frictional forces between the NiTi wires and alumina are attributed to an abrasive interfacial transfer film between the wires and alumina.
Berradja
Abdenacer
A
Departments of Metallurgy and Materials Engineering, Katholieke Universiteit Leuven, Leuven, Belgium.
Willems
Guy
G
Celis
Jean-Pierre
JP
D000388:Air; D000537:Aluminum Oxide / Q000737:chemistry; D003343:Corrosion; D003722:Dental Alloys / Q000737:chemistry*; D003890:Desiccation; D017276:Friction; D006801:Humans; D006813:Humidity; D008153:Lubrication; D008422:Materials Testing; D009532:Nickel / Q000737:chemistry*; D009969:Orthodontic Wires; D012965:Sodium Chloride / Q000737:chemistry; 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