Precautions - DENTSPLY PROPEX II User Manual

4. Precautions

Important notice
The use of apex locators alone without a preoperative and postoperative radiograph
is not a recommended practice, since apex locators may not be able to work properly
in all conditions.
It is mandatory to confirm radiographically the working length established using the
apex locator.
It is important to follow the precautions below and pay close attention to any condition
or situation that may influence the electrical conductivity during the procedure.

Inaccurate or incorrect readings are likely to occur in the following cases, all
procedure related:
-
Partially blocked canal.
-
Size of the measuring file differing significantly from the canal diameter. Ideally,
the selected file should be the thickest one capable of reaching the apex.
-
Presence of liquids and/or tissue debris in the access cavity. Prior to the use of
the device, the access cavity must be dried with a cotton pellet in order to
prevent leaking current.
-
Contact of the file or the lip clip with metallic dental structures. Be particularly
careful with patients fitted with metal crowns or bridges.
-
Contact of the file with another instrument.
-
Very dry canal, for instance in the presence of restoration. In this case the canal
must be moistened with an irrigation solution, or with Glyde
-
Contact between the file and the gums (this may cause a false reading indicating
that the apex has been reached).
-
Use of an ultrasonic scaler with the counter electrode attached to the patient
(electrical noise from the scaler could interfere with the apex localization).
-
Use of the apex locator in conjunction with an electric scalpel.
-
Use of a damaged lip clip, hook or fork.

For apex localization, concentrations of NaOCl higher than 5 % may result in
reduced accuracy.
TM
file prep.
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