Abstract
Introduction
The introduction of nickel-titanium (NiTi) files into clinical practice has improved
the quality of canal shaping, but increasing the curvature of the root canal (or the
diameter of the master instrument that prepares the full working length) could result
in more transportation, straightening, and aberration of the canal. Nickel-titanium
instruments are significantly safer and have an extended cyclic fatigue life when
used with a reciprocating movement. The purpose of this study was to compare the shaping
ability of FlexMaster NiTi instruments when used in either continuous or reciprocating
movements.
Methods
Thirty-two Endo Training Blocks ISO 15, 2% taper, 10-mm radius of curvature, and 70°
angle of curvature were prepared, according to the group, with FlexMaster NiTi instruments
either in continuous rotation or in reciprocating (60° clockwise, 40° counterclockwise)
movement. Preoperative and postoperative images of the simulated canals were taken
under standardized conditions. The preoperative and postoperative images were combined
exactly. The amount of resin removed was determined both for the inner (convex) and
the outer (concave) sides of the curvature at 10 different points.
Results
In the most apical third of the canal, the Continuous group produced the largest enlargement
of the canal as compared with the Reciprocating group (P < .05). In the apical third, the Continuous group displayed significantly greater
enlargement of the canal at the external side.
Conclusions
The shaping of simulated canals is more centered by using a reciprocating motion when
compared with continuous rotation, but the reciprocating motion could be more time-consuming.
Key Words
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Journal of EndodonticsAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Cleaning and shaping the root canal.Dent Clin North Am. 1974; 18: 269-296
- The effect of canal preparation on the formation and leakage characteristics of the apical dentin plug.J Endod. 1984; 10: 308-317
- Rotary NiTi instrument fracture and its consequences.J Endod. 2006; 32: 1031-1043
- [Advantages and limits of nickel-titanium instruments for root canal preparation: a review of the current literature].Schweiz Monatsschr Zahnmed. 2005; 115: 1000-1005
- An initial investigation of the bending and torsional properties of Nitinol root canal files.J Endod. 1988; 14: 346-351
- Torque during canal instrumentation using rotary nickel-titanium files.J Endod. 2000; 26: 156-160
- Canal shapes produced sequentially during instrumentation with Quantec LX rotary nickel-titanium instruments: a study in simulated canals.Int Endod J. 2000; 33: 346-354
- Rotazione alternata nell’uso degli strumenti in nichel-titanio.G Ital Endod. 2002; 16: 79-84
- Fracture rate of nickel-titanium instruments using continuous versus alternating rotation.Endodontic Practice Today. 2008; 2: 193-197
- Extended cyclic fatigue life of F2 ProTaper instruments used in reciprocating movement.Int Endod J. 2010; 43: 1063-1068
- Lifespan of one nickel-titanium rotary file with reciprocating motion in curved root canals.J Endod. 2010; 36: 1991-1994
- Canal preparation using only one Ni-Ti rotary instrument: preliminary observations.Int Endod J. 2008; 41: 339-344
- Properties of endodontic hand instruments used in rotary motion: part 2—instrumentation of curved canals.J Endod. 1995; 21: 493-497
- Efficiency of rotary nickel-titanium FlexMaster instruments compared with stainless steel hand K-Flexofile: part 1—shaping ability in simulated curved canals.Int Endod J. 2002; 35: 505-513
- Endodontic hand instruments: cutting efficiency, instrumentation of curved canals, bending and torsional properties.Endod Dent Traumatol. 1997; 13: 201-210
- Alternating versus continuous rotation: a comparative study of the effect on instrument life.J Endod. 2010; 36: 157-159
- Shaping ability of three ProFile rotary instrumentation techniques in simulated resin root canals.J Endod. 2000; 26: 719-723
- Suboptimal debridement quality produced by the single-file F2 ProTaper technique in oval-shaped canals.J Endod. 2010; 36: 1897-1900
- Micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file.J Endod. 2011; 37: 517-521
- Shaping ability of rotary nickel-titanium systems and nickel-titanium k-files in separable resin blocks.G Ital Endod. 2005; 19: 159-161
- The “balanced force” concept for instrumentation of curved canals.J Endod. 1985; 11: 203-211
Article info
Publication history
Published online: August 16, 2011
Identification
Copyright
© 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.
