Nickel-titanium rotary instruments are important adjuncts in endodontic therapy. This review attempts to identify factors that influence shaping outcomes with these files, such as preoperative root-canal anatomy and instrument tip design. Other, less significant factors include operator experience, rotational speed, and specific instrument sequence. Implications of various working length defini...

introduction: root canal preparation techniques may cause postoperative pain. the aim of the present study was to compare the intensity of postoperative pain after endodontic treatment using hand files, single file rotary (oneshape), and single file reciprocating (reciproc) systems. methods and materials: in this single-blind, parallel-grouped randomized clinical trial a total of 150 healthy pa...

BACKGROUND Root canal preparation using rotary nickel-titanium instruments has been reported to be superior to hand instrumentation in terms of root canal shape, centring and frequency of procedural errors. The purpose of this study was to evaluate canal preparations using a sequential silicone impression technique to assess root canal morphology. METHODS Pre-operative canal impressions were ...

The aim of root canal preparation is to clean and shape the root canal system while maintaining the original configuration. However, traditional hand instruments often failed in achieving these objectives, especially when used in severely curved canals. Over the years, many nickel-titanium rotary instruments have been developed to improve root canal preparation. More flexible files made of nick...

AIM To investigate the effects of cryogenic treatment on nickel-titanium endodontic instruments. The null hypothesis was that cryogenic treatment would result in no changes in composition, microhardness or cutting efficiency of nickel-titanium instruments. METHODOLOGY Microhardness was measured on 30 nickel-titanium K-files (ISO size 25) using a Vicker's indenter. Elemental composition was me...

objectives: the purpose of this study was to evaluate the resistance to fatigue failure of five different nickel-titanium rotary files in three different curved trajectories. materials and methods: a total of 150 neoniti a1, race 25.06, mtwo 25.06, twisted file 25.06 and protaper next x2 files with the tip size of 25 were tested (n=30 for each group). three groove types simulating curved canals...

instruments have been traditionally used with a continuous rotary motion, but more recently, a new approach to the use of nickel-titanium instruments in a reciprocating movement has been introduced by Yared (2004). The clockwise (CW) and counter-clockwise (CCW) rotations used by Yared were four-tenths and two-tenths of a circle respectively, and the rotational speed utilized was 400 rpm. The co...

he aim of this study was to evaluate the apical displacement produced by different rotary nickel-titanium instruments, testing the hypothesis that rotary systems with nickel-titanium instruments produce lower mean values of apical displacement than stainless steel hand instruments. A total of 100 maxillary permanent first molars were selected for the study. The mesiobuccal roots were sectioned ...

AIM The aim of the present study was to compare the resistance to cyclic fatigue of Hyflex® (Coltene-Whaledent, Allstatten, Switzerland) size 40 taper.04 nickel titanium instruments used in continuous rotation versus the use with a reciprocating motion. The null hypothesis was that different file motions had no influence on the lifetime of instruments subjected to a cyclic fatigue test. METHO...

Due to its pseudo elastic behavior, the nickel-titanium (nitinol) alloy has been used in the manufacture of endodontic instruments in recent years, being especially useful for curved canals preparation. Extensive research has been carried out to improve the wear resistance of the nitinol instruments without create modifications in the bulk of the files. The purpose of this work was to measure t...