VDW.GOLD® - Vdw-dental.com

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Problem Possible Cause Solution
THE APEX LOCATOR IS
OVER-SENSITIVE,
DETERMINING THE
APEX PREMATURELY,
i.e. too short length
determination
THE APEX LOCATOR
DOES NOT MEASURE
AT ALL as the electric
circuit is not complete,
i.e. no or less LEDs are
illuminated and do not
accurately represent
the file movement in
the root canal
Short circuit due to excess liquid (irrigation solution,
saliva, blood) in the pulp chamber.
Direct contact of the file with the gingiva or gingival
proliferations, e.g. a fractured metal crown.
Direct contact of the file with metal restorations (crown,
parapulpal post, amalgam filling).
Lateral root canal.
Juvenile root canal with large apex diameter.
(Direct electric current from metal to gingiva or to the
parodontium creates a leakage current causing
premature display reading of the foramen apicale)
Calcified or obliterated canal.
Extremely dry root canal.
Blocked root canal due to retreatment with residues of
previous isolating filling material / blocked root canal by
remnants of medicated substance (e.g. calcium hydroxide)
As stand alone measurement: ISO size of the measuring
file might be too small for a large root canal.
Lip clip not properly touched to mucosa.
As stand alone measurement: measuring file incorrectly
attached to the file clamp, i.e. really clamped onto the
metal shaft below plastic handle?
Damaged measurement cables.
• Dry the access cavity with a cotton pellet / air-blower.
• In case of excess blooding wait until it can be stopped.
• Ensure adequate preparation filling, and/or
electro-cauterise.
• Use rubber dam to isolate the working area.
• Use the contra-angle sleeve.
• Carefully enlarge access cavity, put some flow
composite on it for isolation.
• Repeat determination.
• Accurate measurement seems not feasible.
• Check the comparative x-ray image for hints.
Catheterisation with ISO 06/ 08 file until working length.
• Rinse root canal with a NaOCl solution. Dry the access
cavity with a cotton pellet/ air-blower.
• Take a check x-ray image and completely try to remove
old root filling material remnants prior to measuring /
remove remnants of medicated substance
• If there is no parietal contact use larger ISO size for file.
Important: exactly fitting file leads to precise results.
• Place again lip clip to the patient´s mouth.
• Check cable and plug connections.
• As stand alone measurement: check if contact is good
between file and file clamp.
• Clean the file clamp with ethanol.
• Check visible damage to cable or plug.
en
In case of root fracture or perforation it is impossible to take a precise length
determination as the electric current leaks along the fracture gap.
Electric Length Determination and X-Ray Technique
As radiographs only reproduce in a two-dimensional way a three-dimensional root canal
system, there are a few cases in which the x-ray image and the result obtained with electric
length determination do not match. This does not mean that your VDW.GOLD is not working
properly or that the x-ray image is inaccurate.
These discrepencies in determination occur due to anatomical variation. The actual apical
foramen may not be located at the radiographic apex.