LEDGE FORMATION
 Ledge is a nick formed on the wall surface of a root canal, especially at the curves that prevent the instrument going further towards the apex- because it gets stuck there.
 Caused when instrument that is not pre-curved is inserted into the canal with excessive pressure
 Take a small size file – apply EDTA & do circumferential filing for long time- it will help
smoothen out the ledge by cutting away excessive dentine.
 Thereby bypass the ledge
 EDTA helps dissolve & soften the area - chelation property
 After correction of ledge & bypass, the wall becomes very thin, therefore chances of perforation - most important complication

 Correction at furcation
a) Stop RCT
b) Place MTA / CaOH / GIC
c) Thus the form of a barrier
d) Continue with RCT
e) Or OBT only after healing
 Management of perforation is done after BMP & before OBT

PERFORATION
a. At furcation / coronal 3rd – good prognosis
b. At middle 3rd / apical 3rd – poor prognosis
c. If perforation at apical 3rd – poor prognosis
d. If at furcation – best prognosis

STRIPPING
 Danger zone
 Mand – mesial aspect of distal root canal- inside aspect
of the curved area
 Treated with MTA
 Rotary instruments
 Due to excessive flaring of canals