title: Comparison of mechanical properties of beta-titanium wires between leveled and unleveled brackets: an in vitro study.
abstract: BACKGROUND
  The objective of this study is to evaluate the force-deflection behavior of beta-titanium alloy wires between two leveled and unleveled bracket alignment scenarios using a three-point bending test.
  
  
  METHODS
  Six groups of ten beta-titanium alloy wire segments (0.017 × 0.025-in. diameter) of different manufacturers (Orthometric, Ortho Organizers, GAC, Morelli, and Ormco) were used. Both brackets were bonded to an acrylic jig with a 10-mm interbracket distance. A 1-mm deflection test in two hypothetical conditions (with aligned brackets and by simulating a 2-mm horizontal displacement of the brackets) was explored. Forces of activation and deactivation of the wires during both tests were compared by an analysis of variance (ANOVA) tests followed by a Tukey test.
  
  
  RESULTS
  A statistically significant difference was found in the force-deflection behavior between some of the wires in both simulated in vitro conditions. For the leveled-type alignment scenario, the differences between wires were up to 70 g (range 110 to 179 g). For the unleveled-type alignment scenario, these differences were up to 65 g (range 111 to 175 g).
  
  
  CONCLUSIONS
  The study showed some significant differences in forces generated during activation and deactivation among the five types of beta-titanium wires tested. In comparing leveled and unleveled brackets during activation, only Orthometric Beta Flexy and Ormco Beta-titanium were different between them.
authors.forename: Natalia Martins
authors.initials: NM
authors.lastname: Insabralde
authors.forename: Thaís
authors.initials: T
authors.lastname: Poletti
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Conti
authors.forename: Paula Vanessa
authors.initials: PV
authors.lastname: Oltramari-Navarro
authors.forename: Murilo B
authors.initials: MB
authors.lastname: Lopes
authors.forename: Carlos
authors.initials: C
authors.lastname: Flores-Mir
authors.affiliation: Department of Orthodontics, University of North Parana, UNOPAR, Londrina, Paraná, Brazil. marcioralmeida@uol.com.br.
authors.forename: Marcio Rodrigues
authors.initials: MR
authors.lastname: de Almeida
mesh_terms: D003722:Dental Alloys / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D006801:Humans; D008422:Materials Testing; D055595:Mechanical Phenomena; D009532:Nickel / Q000737:chemistry; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D018583:Pliability; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D003722:Dental Alloys; C023988:beta titanium; C040654:titanium nickelide; D009532:Nickel; D014025:Titanium