Transcript Errors in endodontic cavity preparations & their management

Errors in
endodontic cavity
preparations &
their management
Endodontic errors are not common problem in our
daily endodontic practice but definitely a very
embarrassing situation which may occur during
endodontic procedures like:
•Access cavity preparation.
•Biomechanical preparation of the root
canal
system.
Errors are:
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Coronal perforation:
Lateral perforation:
Cervical perforation
Mid root perforation
Apical perforation
Bifurcation perforation
Ledge formation
Transportation
Gouging :
Zipping :
Elbo
Coronal Perforation
Causes:
Anatomic configuration
Inclination of tooth
Difficult accessibility
Mis direction of bur
Detection:
Saliva comes in the access cavity
Irrigation solution goes into the mouth
Patient notice the unpleasant taste
Management
•Needs immediate repair
•Isolation of the tooth
•Free from contamination
•Intracoronally repaired by using cavit
Zinc oxide calcium sulphate, zinc
sulphate, glycol acetate, polyvinyl
acetate resin, polyvinyl chloride
acetate,
triethanolamine,
colour
pigment
Lateral of perforation (Cervical)
Causes
• Mis direction of bur
• Inappropriate use of Gates Glidden Drill deep in the
canal
• During location of canal orifice
Detection:
• Bleeding in the access cavity
• Radiograph (Place a file through the opening and a
radiograph is taken for the confirmation that the file is
not in the canal)
Lateral of perforation (Cervical)
Management :
•Isolation of the tooth
•Free from contamination
•Control of Bleeding
•Location of perforation
•Location of the canal orifices
•Insertion of the thickest file in the canal
opening up to 5mm below the level of
perforation.
•Calcium hydroxide paste (Dycal) is packed
into the perforation and allowed to set
•Soft mix of amalgam is gently packed over
the calcium hydroxide paste.
•After Initial setting of the filling material the
file is gently removed.
•RCT should be perform as conventional
method.
Prevention:
• In the Anterior teeth the direction of bur should be
parallel in the long axis of the tooth in all plans.
• In molar teeth bur should be directed towards the
large canal orifice.
• The use of bur should be limited to the roof of pulp
chamber.
Bifurcation
perforation
Bifurcation perforation:
Causes :
• Mis direction of bur
• Careless use of instruments
• Inadequate study of the tooth both clinically and
radiographically
Detection :
• Profuse bleeding in the pulp chamber
• Radiograph (Place a file through the opening and
radiograph is taken for the confirmation that the file is
not in the canal.
Furcation Entrance
Entrance:
the transitional area between the undivided
and the divided part of the root
Fornix:
the roof of the furcation
Management
Immediate repair to minimize of the injury
tooth and supporting tissue.
Control of Bleeding
Location of perforation
Calcium hydroxide paste (Dycal) should be
packed into the perforation area and allowed
to set.
Soft mix of amalgam is gently packed
over the calcium hydroxide paste.
RCT should be perform as conventional
method.
Prevention :
Through study of the anatomic
configuration
The use of bur should be limited within
the pulp chamber
Mid root perforation (Striping)
Mid root perforation (Striping)
Stripping is a lateral perforation caused
by over instrumentation through a thin
wall in the root canal & is most likely
to happen on the inside or concave
wall of a curved canal.
Causes :
•Over zealous instrumentation in
the mid-root areas
•Not use precurved instruments.
Identification :
•Appearance of blood
•Sudden complain of pain by the
patient
precurved instruments
Precurvature
of instruments
Management:
•Both internal and external repair may be
required.
•A small area may be sealed from inside
the tooth.
•A large one required surgical repair.
•International re-implantation can be
considered.
Prevention :
•Careful exploration and instrumentation.
•Straight line access to orifice.
•The flexible files (Ni-Ti files) should be used.
•Large
diameter
instruments
avoided.
•Use precurved instrument.
should
be
Apical perforation
Apical perforation
Causes :
• Uncontrolled instrumentation
• Ledge formation
Identification :
• Sudden appearance of fresh bleeding from the
canal.
• Pain during canal preparation.
• Sudden loss of apical stop.
Management :
•Established a new working length.
•Creation an apical seal.
•Obturation to its proper working length.
Ledge formation
Ledge formation
Causes:
• Insertion of uncurved instruments.
• Large instrument out of sequence.
• Inflexible instrument in curved canals.
• Poorly designed access cavity.
• Over enlargement of the curved canals.
Indefication:
•Instrument should be no longer be inserted
into the canal to the full working length.
•Loss of normal tactile sensation of the tip of
instrument binding in the lumen which confirm
hitting a solid wall
Management :
• Location the ledge by a radiograph and verification the
depth
• Irrigate the canal copiously
• Explore the ledge area with a small file No 6, 8, 10, 15 in
which a precurvature has been made form the tip
extending about 3 mm up the blade.
• The curved tip should be pointed toward the wall opposite
the ledge.
•Once the ledge is bypassed start circumferential
filling till be ledge is removed
•Use a lubricant irrigate frequently to remove the
dentine chips
•If the ledge cannot be bypassed then clean, shape
and obturate the canal at that level
•If endodontic treatment fails then alternative
treatment such as roof end filling hemisection may
be considered.
Prevention :
•Accurate radiograph study
•Awareness of canal morphology
•Use of flexible file
•pre curved instruments should be used
•Working length should be followed
Transportation :
•It may be defined as removal of canal
wall structure on the outside curve in
the apical half of the canal due to the
tendency of the files to restore
themselves to their original linear
shape during canal preparation.
Prevention :
•Pre curved instruments should be
used
•Use of smaller or flexible files,
safety files
•Anticurvature filling should be
done.
Transportation :
Causes :
• Rotary action of instruments
• Due to apical curvature of root
Management :
• Instruments should be used in a half circle rotary
action
• Flexible file should be used
Gouging :
When
an
instrument
is
used
with
complete
rotating action
in the apical
curvature,
a
cavity is formed
is
called
gouging.
Zipping
Over preparation of the outer wall of the
apical curvature of the canal with inflexible
instruments will cause zipping.
Zipping :
Causes :
• Failure to used the precurve the instruments
• Rotation of instruments in curved canals
• Use of large stiff instruments
Treatment :
• When a zipping is present theremoplasticized GP
techniques preferred along with Surgical approach can
be consider.
Elbow
• The narrowest part of the preparation is short of
its apical extent & is known as elbow.
• In most case, the obturating material will
terminate at this elbow, leaving an unfilled zipped
canal apical to the elbow.
Elbow
Irrigant-Related Mishaps
Injection of full-strength sodium
hypochlorite out of the apical
foramen.
tissue emphysema caused
by injecting hydrogen
peroxide irrigant into the
tissues
Instrument Aspiration and Ingestion