46
7 Troubleshooting
The canal length meter overreacts or is
too sensitive.
(Measurements are too short. Poor
accuracy. Erratic results.)
Is blood or a chemical solution
over
fl
owing from the opening of the
crown?
If blood or other
fl
uids over
fl
ow the canal,
the current will leak to the gums and
the meter will jump to Apex. Clean the
canal, canal opening and tooth crown
thoroughly.
Is the canal
fi
lled with blood, saliva or
chemical solution?
The canal length indicator bar may
suddenly swing when it breaks the
surface of
fl
uids inside the canal. But
it will return to normal as the
fi
le is
advanced down toward the apex.
Is the tooth surface covered with cutting
debris or chemical solution?
Clean the entire tooth surface.
Is the
fi
le touching the gingival tissue?
This will cause the canal length indicator
bar to suddenly jump all the way to the
“Apex.”
Is there pulp tissue left inside the root
canal?
Accurate measurements cannot be
obtained if a large amount of pulp tissue
is left inside the root canal.
Is the
fi
le touching a metal prosthesis?
Touching a metal prosthesis with the
fi
le
allows a
fl
ow of current to the gingival
tissue or periodontal pocket and will
cause the meter to jump to the “Apex.”
Is the tooth surface infected with
caries?
Current can
fl
ow through the caries
infected area to the gums and prevent
an accurate measurement from being
obtained.
Are there lateral canals or is the tooth
fractured?
The canal length indicator bar may jump
to “Apex” when it reaches the opening
of a lateral canal or the opening of a
fractured tooth that allows the current to
fl
ow to the gingival tissue.
Is a broken crown allowing leakage of
electric current?
A lesion can destroy the apical foramen
through absorption and an accurate
measurement cannot be obtained.
Build up an insulating barrier to stop the
leakage.
Is there a lesion at the apex?
Is the
fi
le holder broken or dirty?
Replace or clean the
fi
le holder.
During a root canal enlargement and
preparation operation, the motor
stops rotation and the
fi
le penetration
prevents it from being pulled out.
Press the push button of the handpiece
in the patient’s mouth to remove the
fi
le.
Then, hold the
fi
le by hand and pull it out
with caution to prevent breakage.
Problem
Response
Check Points