Mechanical properties of multi-force vs. conventional NiTi archwires

  • Luca Lombardo
  • Marianna Ceci
  • Francesco Mollica
  • Valentina Mazzanti
  • Mario Palone
  • Giuseppe Siciliani
Original Article



Mechanical properties along the length of latest generation “multi-force” archwires were measured and compare with commercially available thermally activated and non-thermally activated nickel-titanium (NiTi) archwires.

Materials and methods

A modified deflection test was used to produce load/deflection curves for different positions along the lengths of a sample of 114 NiTi archwires composed by thermal NiTi, non-thermal NiTi, two types of multi-force NiTi and one type of multi-force copper archwires of various cross-sections (0.016 × 0.016 inch, 0.016 × 0.022 inch, 0.018 × 0.025 inch and 0.019 × 0.025 inch). The length, slope and mean force expressed were calculated from the resulting unloading plateaus, enabling comparison between types of archwire at different points along their lengths.


Among conventional thermal, conventional nonthermal and multiforce archwires, all parameters investigated were statistically different, whereby the performance of the latter was superior. Multi-force archwires displayed 27% and 31% lighter mean forces in the upper and lower arches, respectively, in addition to 62% and 40% reductions in unloading plateau slope and length, respectively, as compared to conventional CuNiTi wires. Comparison of the different types of multi-force wires tested revealed statistically significant differences in the three parameters, depending on the testing position but irrespective of their cross-section.


Although conventional archwires display identical behaviour along their lengths, as advertised the multi-force archwires do indeed exert a progressive force which differs between anterior, medial and posterior sections. The multi-force wires provide lighter, more prolonged and constant forces than conventional wires without cross-section-dependent variation.


Multi-force archwire NiTi archwires Unloading plateau slope Orthodontic wires 

Mechanische Eigenschaften von Multi-Force- im Vergleich zu herkömmlichen NiTi-Bögen



Die mechanischen Eigenschaften entlang der Multi-Force-Bögen der jüngsten Generation wurden gemessen und mit konventionellen thermisch aktivierten und nichtthermisch aktivierten Nickel-Titan(NiTi)-Bögen verglichen.

Materialien und Methoden

Insgesamt 114 NiTi-Bögen wurden einem modifizierten Biegeversuch unterzogen, um Belastungs-und Deflexionskurven an verschiedenen Positionen entlang der Bögen zu erzeugen. Untersucht wurden Bögen aus thermischem NiTi-, nichtthermischem NiTi-, zwei verschiedene Multi-Force-NiTi-Bögen und ein Multi-Force-Kupfer-Bogen mit verschiedenen Querschnitten (0,016 × 0,016, 0,016 × 0,022, 0,018 × 0,025 und 0,019 × 0,025″). Länge, Steigung und mittlere Kraft wurden aus den resultierenden Entlastungsplateaus berechnet, was einen Vergleich zwischen den Bögen in verschiedenen Bereichen ermöglichte.


Konventionelle thermische, konventionelle nichtthermische und Multi-Force-Bögen unterschieden sich hinsichtlich aller untersuchten Parameter statistisch signifikant, wobei die Ergebnisse bei den letztgenannten besser waren. Multi-Force-Bögen für Ober- und Unterkiefer wiesen 27 bzw. 31 % geringere mittlere Kräfte auf, sowie Entlastungsplateaus mit 62 bzw. 40 % weniger Steigung und Länge im Vergleich zu herkömmlichen CoNiTi-Bögen. Der Vergleich der verschiedenen geprüften Multi-Force-Bögen ergab statistisch signifikante Unterschiede bezüglich der drei Parameter, abhängig von der Prüfposition, aber unabhängig von ihrem Querschnitt.


Während konventionelle Bögen auf ihrer Länge das gleiche Verhalten zeigen, übten die Multi-Force-Bögen, wie erwartet, tatsächlich progressive, zwischen vorderem, mittlerem und hinterem Abschnitt unterschiedliche Kräfte aus. Die Multi-Force-Drähte bieten leichtere, länger anhaltende und konstantere Kräfte als herkömmliche Drähte ohne querschnittsabhängige Variation.


Multi-Force-Bogen NiTi-Bogen Steigung des Entlastungsplateaus Kieferorthopädischer Bogen 


Conflict of interest

L. Lombardo, M. Ceci, F. Mollica, V. Mazzanti, M. Palone and G. Siciliani declare that they have no competing interests.


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Copyright information

© Springer Medizin Verlag GmbH, ein Teil von Springer Nature 2018

Authors and Affiliations

  • Luca Lombardo
    • 1
  • Marianna Ceci
    • 1
  • Francesco Mollica
    • 2
  • Valentina Mazzanti
    • 2
  • Mario Palone
    • 1
  • Giuseppe Siciliani
    • 1
  1. 1.Department of OrthodonticsUniversity of FerraraFerraraItaly
  2. 2.Department of EngineeringUniversity of FerraraFerraraItaly

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