Viana Ana Cecília Diniz, Chaves Craveiro de Melo Marta, Guiomar de Azevedo Bahia Maria, Lopes Buono Vicente Tadeu
Department of Restorative Dentistry, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2010 Oct;110(4):527-33. doi: 10.1016/j.tripleo.2010.05.006.
The purpose of this study was to assess the influence of both the metallurgic and the geometric characteristics of nickel-titanium endodontic instruments on their flexibility.
ProTaper Universal (PTU), K3, and EndoSequence (ES) instruments were evaluated. Their chemical composition and phase constitution were characterized by conventional analytical techniques. Instrument diameter and cross-sectional area were evaluated by image analysis. Flexibility was evaluated in bending tests according to the ISO 3630-1.
K3 presented the highest average bending moment (M(B)), followed by PTU and ES. A linear relationship was found between M(B) and the instrument's diameter and cross-sectional area at 3 mm from the tip. Alloy chemical compositions were similar among the files, but transformation temperatures were lower for K3 instruments, which presented only austenite as a constituent phase.
Nickel-titanium instruments from different manufacturers have unequal behavior related to their flexibility properties. Manufacturing processes changed the phase constitution and transformation temperatures of the instruments investigated and may also have influenced their flexibility.
本研究旨在评估镍钛根管器械的冶金特性和几何特性对其柔韧性的影响。
对ProTaper Universal（PTU）、K3和EndoSequence（ES）器械进行评估。采用传统分析技术对其化学成分和相组成进行表征。通过图像分析评估器械直径和横截面积。根据ISO 3630-1在弯曲试验中评估柔韧性。
K3的平均弯矩（M(B)）最高，其次是PTU和ES。在距尖端3 mm处，M(B)与器械直径和横截面积之间存在线性关系。各锉之间合金化学成分相似，但K3器械的转变温度较低，其仅呈现奥氏体作为组成相。
不同制造商生产的镍钛器械在柔韧性方面表现不同。制造工艺改变了所研究器械的相组成和转变温度，也可能影响了它们的柔韧性。
