Static and Cyclic Load-Deflection Characteristics of NiTi Orthodontic Archwires Using Modified Bending Tests

  • Mahmoud Nili AhmadabadiEmail author
  • Tahereh Shahhoseini
  • Mohamad Habibi-Parsa
  • Maryam Haj-Fathalian
  • Tahereh Hoseinzadeh-Nik
  • Hananeh Ghadirian


Near-equiatomic nickel-titanium (nitinol) has the ability to return to a former shape when subjected to an appropriate thermomechanical procedure. One of the most successful applications of nitinol is orthodontic archwire. One of the suitable characteristics of these wires is superelasticity, a phenomenon that allows better-tolerated loading conditions during clinical therapy. Superelastic nitinol wires deliver clinically desired light continuous force enabling effective tooth movement with minimal damage for periodontal tissues. In this research, a special three-point bending fixture was invented and designed to determine the superelastic property in simulated clinical conditions, where the wire samples were held in the fixture similar to an oral cavity. In this experimental study, the load-deflection characteristics of superelastic NiTi commercial wires were studied through three-point bending test. The superelastic behavior was investigated by focusing on bending time, temperature, and number of cycles which affects the energy dissipating capacity. Experimental results show that the NiTi archwires are well suited for cyclic load-unload dental applications. Results show reduction in superelastic property for used archwires after long-time static bending.


biomaterials intermetallics nonferrous metals 


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Copyright information

© ASM International 2009

Authors and Affiliations

  • Mahmoud Nili Ahmadabadi
    • 1
    Email author
  • Tahereh Shahhoseini
    • 1
  • Mohamad Habibi-Parsa
    • 1
  • Maryam Haj-Fathalian
    • 1
  • Tahereh Hoseinzadeh-Nik
    • 2
  • Hananeh Ghadirian
    • 2
  1. 1.School of Metallurgy and Materials EngineeringUniversity of TehranTehranIran
  2. 2.School of DentistryTehran University of Medical SciencesTehranIran

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