Numerous technological solutions in recent years have significantly improved
the cleaning and shaping of canals and made canal instrumentation simpler,
more efficient and safer. Significantly faster and less stressful canal
instrumentation for the therapist is enabled by the specific design of the
file working part and a special thermal modification of NiTi alloy with a
change in the movement dynamics of the file in the canal. Research has shown
that the problem of cyclic fatigue and torsional stress of the file during
canal preparation can be solved by changing usual continuous rotation of the
file. Dental technology has introduced the technique of reciprocal movements
as an alternative to full file rotation. This change in file rotation
direction during instrumentation, based on the technique of balanced forces,
significantly reduces contact surface with the canal wall, eliminates the
effect of screwing, extends the life of the file and further increases
safety of instrumentation of different canal systems. An important advantage
of changing the usual dynamics of file movements is that the concept of
reciprocal movements is based on the use of only one file, which in addition
to shortening treatment time also makes this intervention safer and with
significantly lower percentage of defects and fractures of NiTi files. The
aim of this paper was to present the concept of canal instrumentation with
NiTi files with reciprocal movements as well as development, properties and
possibility of application of these files in different clinical situations.