endodontic mishap

Dr. MUNEERA GHAITHAN

Endodontic Mistakes

Access related

Instrumentation related

Obturation related

Miscellaneous

E n d o d o n ti c m i s t a k e s : -

• Treating the wrong tooth• Missed canals• Failure to remove all caries and

unsupported structures• Damage to existing restoration• Access cavity perforations• Crown fractures

Access related mistakes

Treating the Wrong Tooth • misdiagnosis• a tooth adjacent to the one scheduled

for treatment was inadvertently opened.

Causes

• Re-evaluation of the patient who continues to have symptoms after treatment

• When the rubber dam has been removed

Recognition

• appropriate treatment of both teeth: the one incorrectly opened and the one with the original pulpal problem

Correction

• arrive at the correct diagnosis• marking the tooth to be treated Prevention

Failure to remove all caries as well as weak and unsupported tooth structure

Leads to contamination and re infection of the prepared root canal with saliva and bacteria conducting to endodontic failure.

Correction: According to the case, sometimes retreatment may be needed.Prevention: Careful remove of all caries and

unsupported tooth structure .

Damage to existing restorationIn preparing an access cavity through a porcelain or porcelain-bounded crown, will sometimes chip.

Correction: Minor porcelain chip can at time be repaired by bounded composite resin to the

crown, however, the longevity of such repairsis unpredictable.

Prevention: Placing a rubber dam clamp directly on the margin of porcelain crown is preventing damage to the crown margin and/or fracture of porcelain.

The solution to prevent damage to an existing permanently cemented crown is to remove it before treatment with little or no damage to the crown.

Access cavity perforations

searching for canal orifices

Perforations of crown

occur

Peripherally through the side of the crown Floor of the

chamber

Recognition

Above the periodontal attachmentThe first sign of an accidental perforation will often be the presence of leakage: either saliva into thecavity or irrigating solution into the mouth.

Access cavity perforations, con’t

When the crown is perforated into the periodontal ligament, bleeding into the access cavity is often the first indication of an

accidental perforation .To confirm the perforation place a small file

through the opening and take a radiograph

Access cavity perforations, con’t

Perforations of the coronal walls above the alveolar crest can generally be repaired intracoronally

without for surgical intervention .Perforations into the periodontal ligament should be done as soon as possible to minimize the injury to the tooth’s supporting tissues .

The material used for the repair should provides a good seal and does not cause further tissue damage

Correction

Cavit, amalgam, calcium hydroxide paste, Super EBA, glass ionomer,gutta-percha, hemostatic agents.

Materials usedMineral trioxide aggregate

Access cavity perforations, con’t

Prognosis:Location of the perforationTime the perforation is open to contaminationAbility to seal the perforation

Prevention:Thorough examination of diagnostic preoperative radiographsClose attention to the principles of access cavity preparation: adequate size and correct location, permitting direct access to the root canals.

A thorough knowledge of tooth anatomy

Access cavity perforations, con’t

CROWN FRACTURE

Causes: Preexisting infraction Recognition: By direct observation

Treatment: Tooth Extraction

Prevention: Reduce the occlusion before working length is established

Infracted crown should be supported with circumferential bands or temporary crowns

Instrumentation related mistakes

-Ledge formation-Canal blockage-Cervical canal perforations-Midroot perforations-Apical perforations-Separated instruments and foreign objects

Instrumentation related mistakes

Ledge is an internal transportation of the canal which prevents positioning of an instrument to the apex in an otherwise patent canal.

LEDGE FORMATION

Causes:-

1-Using straight instruments in curved canal.

2-Packing debris in the apical portion of the canal.

3-Rapid advancement in files sizes or skipping file size.

Ledge formation, con’t

Recognition-:

1-When the instrument can not reach to the full working length.

2-There may be a loss of normal tactile sensation at the tip of the instrument, loose feeling instead of binding in the canal.

3-a radiograph of the tooth with the instrument in place will provide additional information.

Ledge formation, con’t

Correction: Use of a small file, No. 10 or 15 with a small bend at the tip of the instrument.

penetrate the file carefully intothe canal.

Ledge formation, con’t

Once the tip of the file is apical to the ledge, it’s moved in and out of the canal utilizing ultra short push-pull movement with emphasis on staying apical to the defect.

Ledge formation, con’t

Separated Instruments and Foreign Objects:

Instrument breakage is a common and frustrating problem in endodontic treatment which occurs by

improper or overuse of instruments.

When an instrument fracture occurs during root canal preparation procedures, the clinician has to evaluate the treatment options with consideration for the pulp status, the root canal infection, the root canal anatomy, the position and type of fractured instrument

Radiographs showing broken instruments in different levels of curved and straight canals

Separated Instruments and Foreign Objects con’t:

Treatment-:-Use of a small tipped ultrasonic instrument.

Separated Instruments and Foreign Objects con’t:

-Attempt to bypass it with a small file or reamer. Bypassing is made easier with a lubricant. If successful, the canal preparation can be completed and the canal filled.

[thus the instrument segment becomes part of the filling material.

Separated Instruments and Foreign Objects con’t:

If the fragment extends past the apex and efforts to remove it non surgically are unsuccessful, the corrective treatment will probably include apical surgery.

Separated Instruments and Foreign Objects con’t:

Root perforations can be identified as

root perforation

cervical

midroot

apical

creating a ledge and persisting until a perforation develops

wearing a hole in the lateral surface of the midroot by overinstrumentation (canal stripping)

using too long instrument and perforating the apex.

These are usually caused by three errors:

root perforation con’t

Cervical perforations

The cervical portion of the canal is most often

perforated during the process of locating and

widening the canal orifice or inappropriate use

of gate-glidden burs.

root perforation con’t

Cervical perforations con’t

Causes:during the process of locating and widening the canal orifice or inappropriate use of gate-glidden burs.

Recognition:Sudden appearance of blood in the cavityMagnification with either loupes, endoscope, or microscope is useful.

Correction -:the bleeding is stopped and MTA is applied to the perforation.

Cotton should be placed in the chamber and a good temporary filling is placed to allow time for the MTA to set (> 3 hr). Preparation is continued at a subsequent appointment.

Cervical perforations con’t

Midroot perforations

-commonly occur in the carved canal when a ledg has formed during instrumentation, or along inside the curvature of root canal, as it straightened out, i.e. strip perforation.Recognition-:

blood in the canal indicates that a perforation has occurred.Management-:

MTA is the material of choice to close the perforation

Causes-:

1-The file not passing a curved canal

2-not establishing accurate working length

4-Over instrumentation.

Apical perforations

Detection•patient suddenly complains of pain during treatment.

•The canal becomes flooded with hemorrhage.

•The tactile resistance of the confines space is lost.

•Paper point inserted to the apex will confirm a

suspected apical perforation (bleeding at the tip of

paper point)

•Radiographically with the instrument inside.

Apical perforations, con’t

Treatment:-•If the perforation create new foramen:

•One is now dealing with two foramina: one natural, the other lateral. Obturation of both of these foramina and of the main body of the canal requires the vertical compacting techniques with heat-softened gutta-percha.

Apical perforations, con’t

If the perforation is caused by over instrumentation:

corrective treatment include-Re-establishing tooth length short of the original length and then enlarging the canal with larger instruments, to that length.-The canal is then cautiously filled to that length

Apical perforations, con’t

Creating an apical barrier is another technique that can be used to prevent over extensions during root canal filling. Materials used for developing such barriers include calcium hydroxide powder,hydroxyapatite, and , more recently,MTA.

Apical perforations, con’t

OBTURATION-RELATED MISHAPS

OBTURATION-RELATED MISHAPS

Over or underextended root canal fillings Causes:-

over extended filling

Under extended filling

apical perforation

A-Failure to fit the master gutta-percha point accurately.

B-poorly prepared canal ,particularly in the apical part of the canal.

-Recognition of an inaccuracy placed root canal

filling usually takes place when a post

treatment radiograph is examined.

obturation-related mishaps con’t

Correction:-1-underextended filling: treatment by , removal of

the old filling followed by proper preparation & obturation of the canal.

2-overextended filling: is more difficult. An attempt to remove the over extension is sometimes successful if the entire point can be removed with one tug. If the overextended filling can not be removed through the canal ,it will be necessary to remove the excess surgically.

MISCELLANEOUS MISHAPS

• Irrigant-Related Mishaps• Tissue Emphysema• Instrument Aspiration and Ingestion

MISCELLANEOUS MISHAPS

Irrigant-Related Mishaps

• Forcibly injecting NaOCl or any other irrigating solution into the apical tissue can be a disastrous

• The patient may immediately complain of severe pain.

• Swelling can be violent and alarming.

Management:

• Antihistamines, ice packs, intramuscular steroids, even hospitalization and surgical intervention may be needed.

Prevention:• of course, is the only solution!• using passive placement of a modified needle.• The needle must not be wedged in the canal.

Irrigant-Related Mishaps con’t