Conse iv script-10-procedural-accidents-in-endodontics

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Conservative lecture n˚ 10 5.12.012
Our lecture today will be about procedural accidents in endodontics ,
also called endodontics mishaps.
In this lecture we will talk about the definition of endodontics mishaps
and classifications.
The definition of endodontics mishaps or procedural accidents is; both
unfortunate accidents that happen during treatment, some owning to
inattention to detail and others being totally unpredictable.
Ya3ni sometimes it's your fault and sometimes you cannot deal with it.
Classification of endodontics procedural errors:
 Accidents during access preparations
 Accidents during cleaning and shaping
 Accidents during obturation
 Accidents during post space preparation
Proper access opening is the key to insure an errorless procedure during
cleaning and shaping, if it's not gained it will be beginning of procedural
failure, ya3ni the beginning of a good root canal treatment is good access.
Main errors during access opening are:
1. Access cavity perforations
2. Treatment of the wrong tooth
3. Missed canals
4. Damage to an existing restoration

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1. Access cavity perforations:
The prime objective of an access cavity is to provide an unobstructed or
straight line pathway of the apical foramen; ya3ni you have to gain a straight
line access to the apical foramen.
Accidents such as excess removal of tooth structure or perforation, may
occur during attends to locate root canal.
Failure to achieve straight line access is often the main etiologic factor
for other parts of extra canal accident. Ya3ni even intra canal accidents
happen because of inadequate access.
The causes of access perforation:
 you have to know the anatomy and the morphology of tooth,
usually whatever is the tooth, the pulp chamber in most of teeth
located in the center of the anatomic crown; ya3ni not too mesially
nor too distally ,usually in the center.
 The pulp system is located in the long access of the tooth, so if
we had an inclined tooth, keep in your mind; you have to incline
your bur with the long access of the tooth.
 Lack of attention of the degree of either inclination of the tooth in
relation to the adjacent teeth or the alveolar bone; may result in
either gauging or perforation of the crown.
 Failure to check the orientation of access opening during
preparation may result in perforation, ya3ni when you open the access
cavity stop and check, keep checking.
Prevention of access cavity perforation:
 You have to do good clinical examination; as I said the knowledge
of tooth morphology, location and angulations of the tooth and
you have to take many radiographs with different angles.
 We do the access cavity without the rubber dam; not
Instrumentation only the access cavity, also you have to use, after
you open the pulp room, a safe ended bur (without cutting tip).

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 Failure to recognize when the bur passes through the roof of the pulp
chamber if the pulp chamber is calcified may result in gauging or
perforation of the furcation area.
 The (11:58) … and angled RG is necessarily for early perforation
detection.
 Early detection reduces damage caused by continued treatment,
irrigation, cleaning and shaping. Ya3ni if you do perforation you have stop
cleaning and shaping, repair the perforation then you continue cleaning and
shaping and irrigation.
 You have to use appropriate light source during access preparations,
and sometimes you need to use magnifying glasses or even
microscope in difficult cases like calcified canals and pulp chambers.
Recognition and treatment of access perforation:
 Perforations must be recognized early to avoid sub-sequent
damage to the periodontal tissue with intra canal instruments and
irrigants; ya3ni if you continue cleaning the perforation it will cause more
damage.
 Early signs of perforations:
1. Sudden pain, even if the patient is anesthetized if you do a
perforation the patient will have sudden pain.
2. Sudden hemorrhage
3. Burning pain during irrigation
**these three signs are signs of perforations.
 Usually severe post operative pain may result from cleaning and
shaping through an undetected perforation.
 When perforation occurs, patient should be considered for
referral to an endodontist, sometimes they need surgery to repair
the perforations.
Access cavity perforations 2 types:
1. Later perforations: the location and the type of perforation
determine the prognosis;

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 If it's above the crestal bone, the prognosis is preferable.
 The defect can be easily repaired with standard restorative
materials (composite, GIC, amalgam) if it's above the crestal
bone.
 Teeth with perforations below the crestal bone in the coronal
third of the root; they mainly have the poorest prognosis.
 The treatment goal is to position the apical portion of the defect
above the crestal bone.
 In the anterior teeth orthodontics root extrusion is the procedure
of choice; it's an esthetic area, so we'll do extrusion to repair the
perforation.
 In the posterior teeth we do crown lengthening to repair the
perforation
 The material of choice to repair the perforation is MTA (mineral
trioxide aggregate).
For summary:
 Perforations are either above or below the crestal bone.
 It's difficult to repair perforation below the crestal bone.
 So we have to expose the perforation either by extrusion of the
tooth or by crown lengthening.
 Extrusion is for anterior teeth.
 Crown lengthening is when esthetics are not important.
Wiki: Crown lengthening is a surgical procedure performed by a dentist to expose a
greater amount of tooth structure for the purpose of subsequently restoring the
tooth prosthetically. This is done by incising the gingival tissue around a tooth and,
after temporarily displacing the soft tissue, predictably removing a given height
of alveolar bone from the circumference of the tooth or teeth being operated on.

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2. furcation perforations: two types
1. Direct: it's when you're trying to find the canals, it looks like a
punched out defect
 This type should be repaired immediately with MTA.
 The prognosis is good for direct perforation.
2. Stripping or lateral furcation perforation: involves the
furcation site of the coronal root, also involves the furcation
perforation of the coronal site of the furcation.
 The cause of stripping perforation is excessive caring
and size or drill (18:18); while using Gates Glidden it
causes lots of stripping perforations.
 Stripping perforations are generally inaccessible
requiring more elaborated approaches.
 Also we have to use MTA to repair these perforations.
Treatment of access perforations:
 The perforations can be treated either surgical or non surgical,
according to the case and the accessibility of the perforation.
 If you can see the perforation then you can treat it non surgically.
 Traditional materials such as Amalgam, Gutta Percha, ZOE, Cavit
and Calcium Hydroxide may be used to repair the defects.
 But now the material of choice is MTA to repair the defect; it's a
mixture of calcium solphate.
 Surgical treatment; requires more complex restorative procedure
and more demanding oral hygiene from the patient.
 Surgical alternatives to repair the perforation; according to the
case.
 Hemisection
 Bicuspidization
 Root amputation
 Intentional replantation

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 The remaining roots are prolonged to caries, periodontal disease
and vertical root fracture.
 Sometimes when the prognosis is not good consider extraction of
tooth.
Prognosis of the access perforations: depends on the case;
 The location of the defect.
 The time; when it happened during treatment
 The size.
 The absence/presence of periodontal communications to the
defect.
2. treatment of the wrong tooth:
 You have to do good examination.
 RGs.
 You have to open the access cavity before putting the rubber
dam so to treat the exact tooth.
3. Damage to existing restorations:
Sometimes you have to do RCT through a crown so you have to;
 Be careful not to damage the porcelain crown;
 Use a water-cooled smooth diamond point
 Do not force the bur let it cut its own way
 Don't put a rubber dam on the margins of the porcelain crown,
put it under the crown.

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4. Missed canals:
Usually;
 Canals of mesial roots of the maxillary molars and distal roots of
mandibular molars; are the most frequently missed.
 Second canals in lower incisors, Second canals and bifurcated
canals in lower premolars, Third canals in upper premolars are
also missed.
 You have to do adequate access to find all the canals.
Most common procedural accidents are:
1. Ledge formation
2. Artificial canal
3. Root perforation
4. Instrument separation
5. Extrusion of irrigating solution peri-apically
You have to gain good access to prevent these accidents.
1. Ledge formation:
Ledge is created when the original patency of the canal is lost, ya3ni you
no longer can go to the original working length. When we measure at first it was
good, but after cleaning and shaping it was lost – this is ledge formation.
Prevention of ledge formation:
 The canals most prone to ledge are small, curved and long ones.
 You have to do straight line access.

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 accurate working length measurement
 frequent recapitulation and irrigation and also use lubrication
 You have to use 1/8 to 1/4 reaming motion; don't do rotation
with the file.
 Each file must be worked till it's loose before a larger size is used.
Major causes of ledge formation:
 Inadequate straight line access
 Inadequate irrigation with sodium hypochlorite (never with saline)
and lubrication,
 Excessive enlargement of curved canal with a file,
 Packing of debris in the apical portions of the canal.
Management: it's difficult to manage
 You have to bend the file 2-3 mm, and try to find the original
canal by tipping motion, if the original canal is located; the file is
then worked with reaming motion and slight up and down
movement, to clean the original canal.
 If you couldn't find the original canal you have to stop to the new
working length and obdurate the canal, don't try to force the file.
Prognosis: It depends on the case;
 When it happened; after cleaning and shaping or before it
 Size of the ledge
 Sometimes we need surgery to repair the ledge
Lateral perforations are consequence of Ledge. If you continue
incrementing the Ledge you'll make artificial canal and end with a
perforation.
2. Creating an Artificial canal:
Causes:
After you created a ledge, and you're trying to correct it, so you go
wrong way inside the ledge and you force the file, so you make an

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artificial canal (wrong canal) and it's more difficult to correct than the
ledge.
Treatment:
 To obdurate an artificial canal, we should determine if there's
perforation or not.
 If there's no perforation the canal is obturated with a warm Gutta
Percha (vertical technique); it's difficult to obdurate the artificial
canal with the lateral condensation technique.
 If there is a perforation the defect should be repaired surgically.
Prognosis: The same as ledge;
 Depends on the case and when it happened after cleaning and
shaping or if you can reshape the original canal or not.
 Sometimes a good prognosis when u can locate the original
canal, sometimes you have to do surgery or even extraction.
3. Root perforations:
Happens at three levels:
 apical: occurs due to over instrumentation, so to prevent it you
have to prepare a good (proper) working length and don't go
beyond the apical foramen.
 treatment: you have to establish a new working length and
put (sometimes, if the apex is very wide) an MTA plug to
make an apical barrier then you put the Gutta Percha
 Sometimes you have to use more than one master cone
and put solvent (like Chloroform) and make a large master
cone than fit the new apical foramen (the larger one).
 Middle:

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 Treatment: the goal is to clean and shape and obdurate the
root canal system; if you cannot you have to do surgery or
even extraction.
 Prognosis: Depends on the size of the perforation, the
location and the timing between discovering it and repair.
 Cervical (Coronal): Occurs during access preparation; as the
operator attempts to locate canals, or occurs during plane
procedures using files or Gates Glidden.
 Treatment and prognosis: repair stripping perforation is
very difficult; the defect usually is inaccessible for
adequate repair.
 Attempt should be made to seal the defect but you have to
be careful to seal the defect and maintain the potency of
the original canal.
4. Separated Instruments:
Etiology:
 Limited flexibility and strength of the intracanal instruments.
 Combined with improper use that may result in intracanal
instrument separation.
Prevention:
 Check the instrument before using it.
 Don't use H-files.
 Check the flutes of the file before use.
 Check the finger spreaders and plugers.
Recognition of separated instrument:
 Removal of shorten file with blunt tip from a canal with a
subsequent loss of patency to the original length; ya3ni getting out a
file shorter in length and you can't go to the working length anymore.
 A radiograph is essential for confirmation of a broken instrument.

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Prevention of separated instruments:
 Recognize physical properties and stress rotation of file.
 Do lubrication and irrigation.
 Each instrument should be examined before use; small files must
be replaced (one time -use for # 8, 10, 15).
 Each file size worked in the canal until it's very loose before the
next file size used.
 In the clinic we use stainless steel-files, Ni-Ti files usually don't show
visual signs of fatigue similar to untwisting of steel files; they should
be discarded before visual signs of untwisting.
Treatment: there are 3 options;
1. Remove the instrument, if you can
2. By pass it
3. Prepare and obdurate coronal to the broken instrument.
 YOU SHOULD TRY TO REMOVE IT .If you couldn't, try to bypass it,
the third option is to clean and obdurate coronal to the separated
instrument.
Prognosis:
 Depends on how much of the canal left undebrided and
unobtureated apical to the instruments remains.
 Prognosis is best when the separation of a large instrument
occurs in the last stages of preparation (after finishing of cleaning
and shaping).
 ALWAYS TELL THE PATIENT, for medico-legal reasons. If the case
is difficult refer the patient.
5. Extrusion of an irrigant:
 Very dangerous accident; SODIUM HYPOCHLORIDE ACCIDENT; be
careful when you irrigate, don't wedge the irrigating needle
inside the canal (it should be loose).

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 Sudden prolonged and sharp pain during irrigation followed by
rapid increasing swelling usually indicates penetration of solution
in the peri-radicular tissues.
 No reason to prescribe antibiotics. Follow up the patient;
sometimes needs medical intervention.
Aspiration or ingestion:
 It's a serious event but easily avoided by proper precautions; USE OF
RUBBER DAM.
 Never do instrumentation without rubber dam.
 Instrument either goes to the airway or alimentary tract.
 The patient requires immediate referral; surgical removal is required
for some swallowed instruments and all aspirated instruments.

Appropriate cleaning and shaping are the keys to prevent obturation
problems.
Adequate prepared canals are obturated without mishaps but
sometimes problems occur either UNDERFILLING OR OVERFILLING OR
VERTICAL ROOT FRACTURE.
Underfilling:
The etiology:
 Is underprepared canal
 Sometimes there's a natural barrier (calcified canal; you can do
nothing )
 Ledge creation
 Insufficient caring
 Poorly adapted master cone
 Inadequate condensation pressure

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Treatment: If you have inadequate under filled Gutta Percha you have
to remove it and do re-treatment.
Overfilling:
Causes:
 Over instrumentation
 Root resorption
 Open apex.
Treatment and prognosis:
 You have to do re-treatment and sometimes you need surgical
intervention to remove the overfilled obturation.
 To avoid overfilling you have to work in a good working length;
customize master cone by applying solvent on the tip of the
Gutta Percha.
 Signs and symptoms of endodontics failure appear, apical surgery
may be required.
 Long term prognosis is dictated by clarity of the apical seal and
the amount of the biocompatibility of the extruded material
(MTA is biocompatible and it will not cause failure), host
resistance, toxicity and sealing ability of the filling material.
Vertical root fracture:
Etiology: Many factors causing root fracture:
 Root canal treatment and associated factor such as Post
placement main causes of vertical root fracture.
 Post cementation is the principal cause.
 the second cause is excessive application of condensation forces
during lateral condensation;
Prevention: the best means are appropriate canal preparation and use
of balanced pressure during obturation.

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 Long standing vertical root fracture are often associated with narrow
periodontal pocket as well as radiolucency (J-shaped radiolucency).
 To confirm the diagnosis; excavatory surgery or removal of the
restoration is necessary.
To prevent post space perforation you have to remove the Gutta Percha
with heated plugger before we use the drill, don't force the drill inside
the canal; move the drill in sequence from the smaller to the larger.
Indicators of post space perforation:
 Appearances of fresh blood
 Sudden pain
 Sudden hemorrhage
 Lateral radiolucency along the root or perforation site.
Treatment and prognosis: depends on the size and location of the
perforation.
Management:
 Is surgical if can't be removed
 if you can remove the post, you can repair it in a non-surgical with
MTA
 teeth with small root perforation that are located in the apical
region are accessible for surgical repair and have better
prognosis than those that have large perforation that are close to
the gingival sulcus or inaccessible .
Thank you and sorry for any mistake
Done: by Ward Abu Nassar & Sara Ibdiwi
Group 8 into "7arshan mogzam ta7t elmazgan : P"