41
4. Usage
If the canal is extremely dry,the meter may not move until
the
fi
le is quite close to the apex.
In this case, try moistening the canal with hydrogen
peroxide or saline.
Extremely dry canal
The meter will not move if the canal is blocked. Open the
canal all the way to the apical constriction to measure it.
Blocked Canal
Thoroughly remove all cutting debris on the tooth.
Thoroughly remove all the pulp inside the canal; otherwise
an accurate measurement cannot be obtained. If granulation
penetrates into the root canal, the meter may wrongly detect
the granulation as the apex.
Cutting debris on tooth, Granulation, Pulp inside canal
Granulation,
pulp
Debris
Accurate measurement cannot be obtained if the
fi
le touches
a metal prosthesis that is touching gingival tissue. In this
case, widen the opening at the top of the crown so that
the
fi
le will not touch the metal prosthesis before taking a
measurement.
Crown or metal prosthesis touching gingival tissue
Crown
In this case, electrical leakage through the caries infected
area to the gums will make it impossible to obtain an accurate
measurement.
Caries touching the gums
Caries
X-ray Tube
Electrical Meter Readings and Radiography
Sometimes the electrical meter readings and the X-ray image will not correspond. This
does not mean that the root canal length measurement function is not working properly
or that the X-ray exposure is a failure. Depending on the angle of the X-ray beam, the
apical foramen may appear to be located di
ff
erently than it actually is.
In the example, the X-ray often seems to show that the position of apical foramen is
deviated to the crown side because the actual foramen does not correspond with the
anatomical apex.
Actual root canal
X-ray Film