Please use this identifier to cite or link to this item: http://hdl.handle.net/1843/57157
Type: Artigo de Periódico
Title: Cyclic flexural fatigue resistance of NiTi Controlled Memory and Blue Technology instruments after torsional preloading
Authors: Túlio César Modesto
Eufemia Carolina Pelaez Acosta
Pedro Damas Resende
Érika Sales Joviano Pereira
Isabella Faria da Cunha Peixoto
Vicente Tadeu Lopes Buono
Ana Cecília Diniz Viana
Abstract: Objective: The aim of this study was to evaluate the influence of torsional preloading on the cyclic flexural fatigue resistance of thermally treated NiTi instruments. Material and Methods: Ten new instruments New Hyflex CM (HF 30.06; Coltene/Whaladent Inc.), Typhoon CM (TYP 30.06; Clinician's Choice Dental Products) and Vortex Blue (VB 30.06; Dentsply Tulsa Dental) were chosen, based on geometry and specific characteristics of the manufacturing process. The new instruments of each system were tested in a bench device to determine their fatigue resistance through mean value of number of cycles to failure (Nf) (Control Group – CG). Another group of 10 new HF, TYP and VB instruments were submitted to 20 cycles of torsional straining between 0° and 180° (Experimental Group – EG) and then submitted to fatigue until rupture under the same conditions of the CG. Tested instruments were examined by scanning electron microscopy (SEM). Data were analyzed using one-way analysis of variance and post hoc Tukey’s test (α=.05). Results: Higher fatigue resistance was accomplished by HF instruments, followed by VB and TYP (p<0.05). During the torsional preloading, the lowest mean torque value was observed for TYP instruments (p<0.05). The torsional preload caused a significant reduction in the Nf values (p<0.05) of about 20%, 39% and 45% for instruments HF, VB and TYP, respectively. Longitudinal cracks, generated during the torsional preloading, were present in VB files, but were not observed in the CM instruments (HF and TYP). Conclusions: In conclusion, the flexural fatigue resistance of thermally treated instruments is diminished after cyclic torsional loading.
Subject: Endodontia
Memória
language: por
metadata.dc.publisher.country: Brasil
Publisher: Universidade Federal de Minas Gerais
Publisher Initials: UFMG
metadata.dc.publisher.department: ENG - DEPARTAMENTO DE ENGENHARIA METALÚRGICA
FAO - DEPARTAMENTO DE ODONTOLOGIA RESTAURADORA
Rights: Acesso Aberto
metadata.dc.identifier.doi: https://doi.org/10.1590/1678-7757-2018-0144
URI: http://hdl.handle.net/1843/57157
Issue Date: 2018
metadata.dc.url.externa: https://www.scielo.br/j/jaos/a/SKdV3YwtWF6cCzRgzdy39Kk/?lang=en#
metadata.dc.relation.ispartof: Journal of Applied Oral Science
Appears in Collections:Artigo de Periódico



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