• Institution: LOCKSS

Influence of Friction Resistance on Expression of Superelastic Properties of Initial NiTi Wires in “Reduced Friction” and Conventional Bracket Systems

  1. Natalie Reznikov naoree{at}gmail.com1
  2. Gilad Har-Zion gilad9{at}012.net.il2
  3. Idit Barkana iditbarkana{at}yahoo.com2
  4. Yosef Abed abedy{at}cc.huji.ac.il2
  5. Meir Redlich mredlich{at}bezeqint.net2
  1. 1Faculty of Dental Medicine, Hadassah-Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel
  2. 2Department of Orthodontics, Faculty of Dental Medicine, Hadassah-Hebrew University, P.O. Box 12272, 91120 Jerusalem, Israel


Objectives. The aim of this study was to assess the influence of resistance to sliding on expression of superelastic properties of NiTi wires.

Methods and Materials. A three-point bending test was performed for 0.014 NiTi wire engaged in self-ligating (Damon, SmartClip, In-Ovation) and conventional brackets (Victory) ligated with regular and reduced friction modules (Slide). The wire was deflected in the buccal direction and allowed to straighten. The maximum load, unloading plateau and unloading capacity were registered.

Results. The lowest activation load was required in the active self-ligating group (In-Ovation Formula N) and reduced friction module group (Victory/Slide Formula N), followed by the passive self-ligating systems (Damon Formula N, SmartClip Formula N). Higher activation load was obtained in the conventionally ligated group (Victory/module Formula N). Unloading plateau phase with the load magnitude ranging from Formula N (In-Ovation) to Formula N (Slide) was distinct in all groups but one (Victory).

Conclusions. Higher friction at flanking points reduces the net force delivered by the wire. Unloading plateau phase of NiTi load-deflection curve disappears in the conventionally ligated group thus indicating to an incomplete expression of NiTi superelastic properties. A rigid passive bracket clip amplifies resistance to sliding in an active configuration and produces a permanent deflection of the wire.

  • Received May 26, 2009.
  • Revision received August 2, 2009.
  • Accepted September 8, 2009.

This Article

  1. J Dent Biomech vol. 1 no. 1 613142