Preparation of artificial L-shaped canals with nickel-titanium rotary files*

Introduction. The aim of endodontic treatment is
to remove the pulp and to shape the root canal with
respect to the original anatomy. In order to shorten
the working time and to reduce the risk of procedural
errors, nickel-titanium rotary files are used in canal
preparation. The rotary instruments vary in taper,
cross-sections of working parts, manufacturing
process, as well as direction and extent of rotation
during shaping. Aim of the study. To compare the
shaping ability of three rotary instruments in simulated
L-curved canals. Material and methods. Thirty resin
blocks with simulated L-curved canals were used in
this experimental study. The blocks were divided
into three groups (ten blocks in each). The canals
were prepared to an apical size 25 according to the
manufacturer’s recommendations. Pre-operative and
post-operative photographs were taken and images
were superimposed by using the GIMP 2.6 program.
The amount of material removed from canal walls,
apical transportation and changes in the working length
were measured. Results. The most central preparation
was provided by WaveOne Gold as compared to the
other systems. The smallest change in the working
length was noted after Hyflex CM instrumentation.
The statistically significant differences were detected
between ProTaper Universal and Hyflex CM, and
between ProTaper Universal and WaveOne Gold files