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Effect of movement kinematics on the cyclic fatigue resistance of nickel–titanium instruments
Author(s) -
Karataş E.,
Arslan H.,
Büker M.,
Seçkin F.,
Çapar I. D.
Publication year - 2016
Publication title -
international endodontic journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.988
H-Index - 119
eISSN - 1365-2591
pISSN - 0143-2885
DOI - 10.1111/iej.12453
Subject(s) - reciprocating motion , nickel titanium , cyclic stress , materials science , kinematics , rotation (mathematics) , fracture (geology) , radius of curvature , orthodontics , composite material , curvature , medicine , mathematics , geometry , mechanical engineering , physics , engineering , mean curvature , classical mechanics , gas compressor , mean curvature flow , shape memory alloy
Aim To compare the cyclic fatigue resistance of new generation OneShape and WaveOne instruments when used with different kinematics. Methodology An artificial canal, made of stainless steel with an inner diameter of 1.5 mm, a 60° angle of curvature and a curvature radius of 3 mm, was used for cyclic fatigue test of new generation OneShape and WaveOne instruments. Groups were as follows ( n = 20): 150°–30°, 210°–30°, 360°–30° and continuous rotation. The time to fracture was recorded in seconds, and the data were analysed statistically using a two‐way anova and LSD tests ( P = 0.05). Results Cyclic fatigue resistance was significantly affected by the movement kinematics ( P < 0.001). The cyclic fatigue resistance of the new generation OneShape instruments increased significantly when operated in various reciprocation motions (150° CW –30° CCW , 210° CW –30° CCW and 360° CW –30° CCW ) compared with the continuous rotation mode. New generation OneShape instruments had significantly more resistance to fracture under cyclic loading than WaveOne instruments ( P < 0.001). Conclusions When using new generation OneShape and WaveOne instruments, all the reciprocating motions (150° CW –30° CCW , 210° CW –30° CCW and 360° CW –30° CCW ) resulted in extended fatigue life when compared with continuous rotation.