The frictional behavior of coated guiding archwires.
BACKGROUND
The vast range of orthodontic wires made of different alloys makes it increasingly difficult for orthodontists to judge them. Coated orthodontic wires form a group of innovative guiding archwires.


METHODS
In the present in vitro study the frictional behavior of eight coated wires of different dimensions was investigated in archwire-guided canine retraction in the upper jaw. For this purpose five superelastic nickel titanium alloy wires (Titanol Low Force River Finish Gold and Gold 2: Forestadent, Pforzheim Germany; Titanol Superelastic tooth colored: Forestadent, Pforzheim Germany; BioForce Sentalloy Ionguard: GAC, Central Islip, NY, USA; NITI Imagination: GAC, Central Islip, NY, USA), two beta-titanium wires (TMA Low Friction Ionguard: Ormco, Glendora, CA, USA; TMA Low Friction Ionguard Purple: Ormco, Glendora, CA, USA), and one steel wire (Stainless steel Imagination: GAC, Central Islip, NY, USA) were selected. The coatings were made of Teflon or polyethylene, and by ion implantation. Three uncoated archwires (Rematitan Lite Dimple: Dentaurum, Pforzheim, German; Titanol Low Force River Finish: Forestadent, Pforzheim, Germany; BioForce Sentalloy: GAC, Central Islip, NY, USA) were used for comparison purposes. The force losses due to friction were measured using the Orthodontic Measurement and Simulation System (OMSS).


RESULTS
The results indicated that all coatings can reduce frictional losses compared with an uncoated reference wire by the same manufacturer. Measured frictional losses ranged from 48.3-6.1%, with the Teflon coatings reducing the frictional losses to less than 10% in some cases.


CONCLUSIONS
An unequivocal correlation between the surface roughness and frictional forces of the wires could not be verified by scanning electron microscopy.
Department of Orthodontics, University of Bonn, Germany. pamela.husmann@uni-bonn.de
Pamela
P
Husmann
Christoph
C
Bourauel
Michael
M
Wessinger
Andreas
A
Jäger
D001696:Biomechanical Phenomena; D020099:Coated Materials, Biocompatible; D003481:Cuspid; D017276:Friction; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D009969:Orthodontic Wires; D011138:Polytetrafluoroethylene
D020099:Coated Materials, Biocompatible; D011138:Polytetrafluoroethylene