17
No sound
Check if sound is turned
off?
Turn on the sound.
Problem
Check points
Responses
Display not
steady while
measuring: the
measurement
result is rather
long or shorter;
numerical
display irregular.
Is the lip hook making
good contact with oral
mucosa?
Make sure the lip hook making good
contact with oral mucosa.
Is blood or saliva
overflowing from the
opening of the crown?
Blood, saliva or chemical solutions
that overflow and leak onto the crown
or neck can cause an electrical
shortage. Clean away all overflowing
fluids.
Is the root canal filled with
blood, saliva or chemical
solutions?
The canal length indicator bar may
suddenly jump to “OVER” when it
breaks the surface of fluids inside the
root canal but it will return to normal as
it approaches the apex.
Is the tooth surface
covered with cutting debris
or chemical solutions?
Clean entire tooth surface.
Is the file touching the
gingival tissue?
This will cause the canal length
indicator bar to suddenly jump all the
way to the “OVER”.
Is there pulp tissue left
inside the root canal?
An accurate measurement cannot be
obtained if a large amount of pulp
tissue is left inside the root canal.
Are proximal surfaces
infected with caries?
Caries on proximal surfaces can allow
the current to flow to the gingival
tissue and make it possible to
measure the length of a root canal.
Are there lateral canals or
is the tooth fractured?
The canal length indicator bar may be
opening of a lateral root canal or the
opening of a fractured tooth which
allows the current to flow to the
gingival tissue. This will cause the
