Endodontic treatment (Step Back Technique)
is also known as Telescopic canal preparation or serial root canal preparation.
Step back technique emphasizes keeping the apical preparation small
and producing a gradual taper coronally
This technique was first described in 1960 by Mullaney
basically this technique involves the
the canal preparation into two phases
phase I involves the preparation of apical constriction
and phase II involves the preparation of the remaining canal
Phase I
Evaluate the carious tooth before initiating endodontic treatment
prepare the access cavity, and locate the canal orifices
Establish the working length of the tooth using pathfinder
The working length is the distance between the reference point coronally and the anatomical apex
two ways to determine the working length
first by x ray that taken while the file is inserted in the canal
In this situation Apical foramen is usually found 0.5-1mm
shorter from the radiographic apex
so we need to decrease the length
Second by Electronic apex locators
That designed to determine the canal length by
giving the reading when the file tip is at the apical foramen
first lubricate the instrument for use in apical area
by EDTA or other lubricant
Now insert the first K file into the canal
with considering the working length with gentle
clockwise and anticlockwise rotation
of file with minimal apical pressure is given
Remove the instrument and irrigate the canal
Place the next larger size files to
to the working length in similar manner and again irrigate the canal
Don’t forget to recapitulate the canal with
previous similar number of H file
This breaks up apical debris
which are washed away with the irrigant
Repeat the process until a size 25
or 30 H-file that reaches the working length
that will be the master file or
Recapitulate between the files by
placing it into the working length
Phase II
Place next file in the series to a length 1 mm short of working length
remove it , irrigate and recapitulate
Repeat the same procedure with successively larger files
at 1 mm more shorter from the previously used file
Finally, refining of the root canal is
done by master apical file with
push-pull strokes to achieve a smooth taper form of the root canal
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