2017-06-162017-06-162016-02NEVES, Murilo Gaby et al. Deflection test evaluation of different lots of the same nickel-titanium wire commercial brand. Dental Press Journal Orthodontics, Maringá, v. 21, n. 1, p. 42-46, jan/fev. 2016. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S2176-94512016000100042&lng=pt&nrm=iso>. Acesso em: 16 jun. 2017. <http://dx.doi.org/10.1590/2177-6709.21.1.042-046.oar>.2177-6709https://repositorio.ufpa.br/handle/2011/8707Introduction: The aim of this in vitro study was to compare the elastic properties of the load-deflection ratio of orthodontic wires of different lot numbers and the same commercial brand. Methods: A total of 40 nickel-titanium (NiTi) wire segments (Morelli OrtodontiaTM - Sorocaba, SP, Brazil), 0.016-in in diameter were used. Groups were sorted according to lot numbers (lots 1, 2, 3 and 4). 28-mm length segments from the straight portion (ends) of archwires were used. Deflection tests were performed in an EMIC universal testing machine with 5-N load cell at 1 mm/minute speed. Force at deactivation was recorded at 0.5, 1, 2 and 3 mm deflection. Analysis of variance (ANOVA) was used to compare differences between group means. Results: When comparing the force of groups at the same deflection (3, 2 and 1 mm), during deactivation, no statistical differences were found. Conclusion: There are no changes in the elastic properties of different lots of the same commercial brand; thus, the use of different lots of the orthodontic wires used in this research does not compromise the final outcomes of the load-deflection ratio.Acesso AbertoOrtodontiaElasticidadeFios ortodônticosArtigo de Periódico