Nickel-titanium alloys: a systematic review

• Published in: Dental press journal of orthodontics Vol. 17; no. 3; pp. 71 - 82
• Main Authors: Ferreira, Marcelo do Amaral, Luersen, Marco Antônio, Borges, Paulo César
• Format: Journal Article
• Language: English
• Published: Dental Press International 01-06-2012; Dental Press Editora
• Subjects: DENTISTRY, ORAL SURGERY & MEDICINE; Nickel-titanium wires; Shape memory alloys; Superelasticity; Thermoelasticity; Nickel-titanium wires; Thermoelasticity; Shape memory alloys; Superelasticity
• ISSN: 2176-9451; 2177-6709; 2177-6709; 2176-9451
• DOI: 10.1590/s2176-94512012000300016

OBJECTIVE: A systematic review on nickel-titanium wires was performed. The strategy was focused on Entrez-PubMed-OLDMEDLINE, Scopus and BioMed Central from 1963 to 2008. METHODS: Papers in English and French describing the behavior of these wires and laboratorial methods to identify crystalline transformation were considered. A total of 29 papers were selected. RESULTS: Nickel-titanium wires show exceptional features in terms of elasticity and shape memory effects. However, clinical applications request a deeper knowledge of these properties in order to allow the professional to use them in a rational manner. In addition, the necessary information regarding each alloy often does not correspond to the information given by the manufacturer. Many alloys called "superelastic" do not present this effect; they just behave as less stiff alloys, with a larger springback if compared to the stainless steel wires. CONCLUSIONS: Laboratory tests are the only means to observe the real behavior of these materials, including temperature transition range (TTR) and applied tensions. However, it is also possible to determine in which TTR these alloys change the crystalline structure.