Movements Of Files

03:35 apex, apico coronal filing, balanced force, canals, movement of files in RCT, retreatment, root, Root Canal Treatment, stem winding 1 Comment

1] stem winding,watch winding or twiddling
the file is used with 45 degree rotational movement clockwise and anticlockwise with gentle apical force.The canal becomes enlarged and the file can be moved apically into the root canal.
use-useful when penetrating fine canals and in re-treatment cases.Files are usually precurve prior to use in this way


2] Quarter turn and pull
this causes more aggressive cutting than stem winding and tends to remove more material from the wall.


3]Apical-coronal filing
The file is applied to the wall of the root canal and moved in and out of the canal at an amplitude of 1-2mm. This movement is especially efficient with Hedstrom files.
To ensure that all the walls of the root canal are cut, circumferential filing is done.


4] Balanced force technique


The movement of the file is clockwise and anticlockise and its action is based upon Newton's third law .The file is placed into the canal till it first binds and then advanced further by clockwise rotation, usually through approximately 60 degree. The file cuts into the root canal wall and creates threads in the dentin as it moves apically.This is the powerphase.The anticlockwise rotation, through approx 120 degree is carried out with some apical pressure so that the file does not unscrew out of the canal..


During this movement the threads of the dentin formed during the power phase are cut from the wall.This is so called control phase.
Oten an audible click can be heard which resembles an instrument fracturing but is merely the dentin being cut from the wall. The file is then removed and the flutes cleaned of debris.If difficulty is encountered in removing the file then the small rotation clockwise, of about 30 degree,allows the file to be forced.In nearly all studies where this manipulations of the file has been compared with other methods.The balanced force technique has been shown to be superior in shaping the canal with less likelihood of iatrogenic damage.The reason for this is tha the file i tends to remain more centrally placed within the root canal which means that the canal can be prepared to a large size without compromising the structure of the root. This combination of a larger size and smooth, even flare follows the natural curvature of the canal probably results in a cleaner canal and certainly one that is easier to obturate with GP.