Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature
Autor(a) principal: | |
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Data de Publicação: | 2017 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1016/j.ejwf.2017.08.002 http://hdl.handle.net/11449/175143 |
Resumo: | Objective Assess the changes in the force system of T-loop springs (TLSs) preactivated by bends and curvature, when secured in place with a constant strain over time. Materials and Methods A total of 120 TLSs with dimensions 6 x 10 mm, produced out of 0.017 × 0.025-inch TMA, were randomly divided into two groups of 60 TLSs, each according to what preactivation was going to be used, concentrated bends or gradual curvature. Subgroup 1 was tested immediately and the remaining subgroups were tested after they were secured at 5-mm activation for different periods of time in an interbracket distance of 23 mm. Subgroups 2, 3, 4, 5, and 6 were kept activated for 24, 48, and 72 hours, 1 and 2 weeks, respectively. Using a moment transducer coupled to a digital extensometer indicator adapted to a universal testing machine, the amount of horizontal force, moment, and moment-to-force (MF) ratios were recorded. Results Both groups showed a decrease in force levels over time (P < 0.001 and 0.005 for bend and curvature preactivation, respectively), but with different behaviors. The group preactivated by bends showed a reduction in moments over time (P < 0.001), whereas the group preactivated by curvature did not (P = 0.410). The MF ratio has not changed over time in either group. Conclusions The stress-relaxation effect is more evident on group preactivated by bends. |
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Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvatureBeta-titaniumPreactivationStress relaxationT-loopObjective Assess the changes in the force system of T-loop springs (TLSs) preactivated by bends and curvature, when secured in place with a constant strain over time. Materials and Methods A total of 120 TLSs with dimensions 6 x 10 mm, produced out of 0.017 × 0.025-inch TMA, were randomly divided into two groups of 60 TLSs, each according to what preactivation was going to be used, concentrated bends or gradual curvature. Subgroup 1 was tested immediately and the remaining subgroups were tested after they were secured at 5-mm activation for different periods of time in an interbracket distance of 23 mm. Subgroups 2, 3, 4, 5, and 6 were kept activated for 24, 48, and 72 hours, 1 and 2 weeks, respectively. Using a moment transducer coupled to a digital extensometer indicator adapted to a universal testing machine, the amount of horizontal force, moment, and moment-to-force (MF) ratios were recorded. Results Both groups showed a decrease in force levels over time (P < 0.001 and 0.005 for bend and curvature preactivation, respectively), but with different behaviors. The group preactivated by bends showed a reduction in moments over time (P < 0.001), whereas the group preactivated by curvature did not (P = 0.410). The MF ratio has not changed over time in either group. Conclusions The stress-relaxation effect is more evident on group preactivated by bends.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Adjunct Professor Department of Dentistry UFRN-Federal University of Rio Grande do NortePrivate practice and part-time adjunct faculty of the Orthodontics Graduate Program UNESP–Univ Estadual Paulista Araraquara School of DentistryMSc Student Department of Dentistry UFRN-Federal University of Rio Grande do NorteDepartment of Dental Materials and Prosthesis UNESP–Univ Estadual Paulista Araraquara School of DentistryDepartment of Pediatric Dentistry UNESP–Univ Estadual Paulista Araraquara School of DentistryPrivate practice and part-time adjunct faculty of the Orthodontics Graduate Program UNESP–Univ Estadual Paulista Araraquara School of DentistryDepartment of Dental Materials and Prosthesis UNESP–Univ Estadual Paulista Araraquara School of DentistryDepartment of Pediatric Dentistry UNESP–Univ Estadual Paulista Araraquara School of DentistryFAPESP: 2008/07258–5UFRN-Federal University of Rio Grande do NorteUniversidade Estadual Paulista (Unesp)Caldas, Sergei Godeiro Fernandes RabeloMartins, Renato Parsekian [UNESP]de Araújo, Marcela EmílioGalvão, Marília RegaladoReis, José Maurício dos Santos Nunes [UNESP]Martins, Lídia Parsekian [UNESP]2018-12-11T17:14:34Z2018-12-11T17:14:34Z2017-09-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article98-104application/pdfhttp://dx.doi.org/10.1016/j.ejwf.2017.08.002Journal of the World Federation of Orthodontists, v. 6, n. 3, p. 98-104, 2017.2212-4438http://hdl.handle.net/11449/17514310.1016/j.ejwf.2017.08.0022-s2.0-850289605162-s2.0-85028960516.pdf8223795731605246Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengJournal of the World Federation of Orthodontists0,196info:eu-repo/semantics/openAccess2023-10-08T06:03:22Zoai:repositorio.unesp.br:11449/175143Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T14:18:27.481681Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
title |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
spellingShingle |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature Caldas, Sergei Godeiro Fernandes Rabelo Beta-titanium Preactivation Stress relaxation T-loop |
title_short |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
title_full |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
title_fullStr |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
title_full_unstemmed |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
title_sort |
Effect of stress relaxation in two different preactivation methods of beta-titanium T-loops: bends vs. continuous curvature |
author |
Caldas, Sergei Godeiro Fernandes Rabelo |
author_facet |
Caldas, Sergei Godeiro Fernandes Rabelo Martins, Renato Parsekian [UNESP] de Araújo, Marcela Emílio Galvão, Marília Regalado Reis, José Maurício dos Santos Nunes [UNESP] Martins, Lídia Parsekian [UNESP] |
author_role |
author |
author2 |
Martins, Renato Parsekian [UNESP] de Araújo, Marcela Emílio Galvão, Marília Regalado Reis, José Maurício dos Santos Nunes [UNESP] Martins, Lídia Parsekian [UNESP] |
author2_role |
author author author author author |
dc.contributor.none.fl_str_mv |
UFRN-Federal University of Rio Grande do Norte Universidade Estadual Paulista (Unesp) |
dc.contributor.author.fl_str_mv |
Caldas, Sergei Godeiro Fernandes Rabelo Martins, Renato Parsekian [UNESP] de Araújo, Marcela Emílio Galvão, Marília Regalado Reis, José Maurício dos Santos Nunes [UNESP] Martins, Lídia Parsekian [UNESP] |
dc.subject.por.fl_str_mv |
Beta-titanium Preactivation Stress relaxation T-loop |
topic |
Beta-titanium Preactivation Stress relaxation T-loop |
description |
Objective Assess the changes in the force system of T-loop springs (TLSs) preactivated by bends and curvature, when secured in place with a constant strain over time. Materials and Methods A total of 120 TLSs with dimensions 6 x 10 mm, produced out of 0.017 × 0.025-inch TMA, were randomly divided into two groups of 60 TLSs, each according to what preactivation was going to be used, concentrated bends or gradual curvature. Subgroup 1 was tested immediately and the remaining subgroups were tested after they were secured at 5-mm activation for different periods of time in an interbracket distance of 23 mm. Subgroups 2, 3, 4, 5, and 6 were kept activated for 24, 48, and 72 hours, 1 and 2 weeks, respectively. Using a moment transducer coupled to a digital extensometer indicator adapted to a universal testing machine, the amount of horizontal force, moment, and moment-to-force (MF) ratios were recorded. Results Both groups showed a decrease in force levels over time (P < 0.001 and 0.005 for bend and curvature preactivation, respectively), but with different behaviors. The group preactivated by bends showed a reduction in moments over time (P < 0.001), whereas the group preactivated by curvature did not (P = 0.410). The MF ratio has not changed over time in either group. Conclusions The stress-relaxation effect is more evident on group preactivated by bends. |
publishDate |
2017 |
dc.date.none.fl_str_mv |
2017-09-01 2018-12-11T17:14:34Z 2018-12-11T17:14:34Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1016/j.ejwf.2017.08.002 Journal of the World Federation of Orthodontists, v. 6, n. 3, p. 98-104, 2017. 2212-4438 http://hdl.handle.net/11449/175143 10.1016/j.ejwf.2017.08.002 2-s2.0-85028960516 2-s2.0-85028960516.pdf 8223795731605246 |
url |
http://dx.doi.org/10.1016/j.ejwf.2017.08.002 http://hdl.handle.net/11449/175143 |
identifier_str_mv |
Journal of the World Federation of Orthodontists, v. 6, n. 3, p. 98-104, 2017. 2212-4438 10.1016/j.ejwf.2017.08.002 2-s2.0-85028960516 2-s2.0-85028960516.pdf 8223795731605246 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Journal of the World Federation of Orthodontists 0,196 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
98-104 application/pdf |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1808128345008766976 |