Effect of movement kinematics on the cyclic fatigue resistance of nickel-titanium instruments.

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.

[1]  I D Çapar,et al.  A review of instrumentation kinematics of engine-driven nickel-titanium instruments. , 2016, International endodontic journal.

[2]  H. Arslan,et al.  Comparison of cyclic fatigue resistance of novel nickel-titanium rotary instruments. , 2015, Australian endodontic journal : the journal of the Australian Society of Endodontology Inc.

[3]  A. Elnaghy.  Cyclic fatigue resistance of ProTaper Next nickel-titanium rotary files. , 2014, International endodontic journal.

[4]  C. Shin,et al.  Fatigue life enhancement of NiTi rotary endodontic instruments by progressive reciprocating operation. , 2014, International endodontic journal.

[5]  H. Arslan,et al.  Effects of ProTaper Universal, ProTaper Next, and HyFlex instruments on crack formation in dentin. , 2014, Journal of endodontics.

[6]  N. Velmurugan,et al.  Cyclic fatigue resistance of RaCe and Mtwo rotary files in continuous rotation and reciprocating motion. , 2014, Journal of endodontics.

[7]  R. Piquet,et al.  Effect of asymmetry on the behavior of prototype rotary triple helix root canal instruments. , 2013, Journal of endodontics.

[8]  Shaimaa M Abu el Sadat,et al.  Effect of altering the reciprocation range on the fatigue life and the shaping ability of WaveOne nickel-titanium instruments. , 2013, Journal of endodontics.

[9]  E. Pedullá,et al.  Influence of continuous or reciprocating motion on cyclic fatigue resistance of 4 different nickel-titanium rotary instruments. , 2013, Journal of endodontics.

[10]  Alessio Giansiracusa Rubini,et al.  Influence of different angles of reciprocation on the cyclic fatigue of nickel-titanium endodontic instruments. , 2012, Journal of endodontics.

[11]  G. Plotino,et al.  Cyclic fatigue of Reciproc and WaveOne reciprocating instruments. , 2012, International endodontic journal.

[12]  K. Kum,et al.  Lifespan of one nickel-titanium rotary file with reciprocating motion in curved root canals. , 2010, Journal of endodontics.

[13]  Jun Ni,et al.  Design improvement and failure reduction of endodontic files through finite element analysis: application to V-Taper file designs. , 2010, Journal of endodontics.

[14]  Ikuya Watanabe,et al.  Cyclic fatigue analysis of a new generation of nickel titanium rotary instruments. , 2009, Journal of endodontics.

[15]  Gianluca Gambarini,et al.  Fatigue resistance of engine-driven rotary nickel-titanium instruments produced by new manufacturing methods. , 2008, Journal of endodontics.