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Safety of the factory preset rotation angle of reciprocating instruments.

Authors :
Kim JW
Ha JH
Cheung GS
Versluis A
Kwak SW
Kim HC
Source :
Journal of endodontics [J Endod] 2014 Oct; Vol. 40 (10), pp. 1671-5. Date of Electronic Publication: 2014 Jul 09.
Publication Year :
2014

Abstract

Introduction: This study aimed to investigate the torsional resistance of 2 reciprocating nickel-titanium instruments (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer, Ballaigues, Switzerland]) operated at the maximum rotating angle in a proprietary motor.<br />Methods: With the file tip secured at various levels (3, 4, or 5 mm) of Reciproc R25 and WaveOne Primary, the distortion angles and torsional loads were monitored during counterclockwise movement at 2 rpm until fracture (n = 10 at each level) for a load-distortion graph. The rotation angles and loads at the beginning point of the plateau, the ultimate torsional strength, final fracture angle, and toughness were determined. The data were analyzed using 1-way analysis of variance and the Tukey post hoc test at α = .05. The lateral longitudinal aspect and the fracture cross-section of each specimen were examined by scanning electron microscopy after the test.<br />Results: The rotation angle at the beginning point of the plateau was significantly greater for a binding site farther away from the tip of the instrument for both systems (P < .05), and all were greater than 170° (preset in the dedicated motor from manufacturer). The ultimate strength and toughness also increased significantly at levels farther away from the instrument tip (P < .05). All specimens showed typical topographic features of torsional fracture, including the circular abrasion marks and fibrous dimples near the rotation center after the test.<br />Conclusions: It was determined that the 2 brands of reciprocating files are safe when operated at the rotational angle in the proprietary motor.<br /> (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Details

Language :
English
ISSN :
1878-3554
Volume :
40
Issue :
10
Database :
MEDLINE
Journal :
Journal of endodontics
Publication Type :
Academic Journal
Accession number :
25260743
Full Text :
https://doi.org/10.1016/j.joen.2014.06.002