Endodontic Mistakes Access related Instrumentation related Obturation related Miscellaneous
Access related mistakes•Treating the wrong tooth•Missed canals•Failure to remove all caries and unsupported structures•Damage to existing restoration•Access cavity perforations•Crown fractures
Treating the Wrong Tooth • misdiagnosis Causes • a tooth adjacent to the one scheduled for treatment was inadvertently opened. • Re-evaluation of the patient who continuesRecognition to have symptoms after treatment • When the rubber dam has been removed • appropriate treatment of both teeth: theCorrection one incorrectly opened and the one with the original pulpal problem • arrive at the correct diagnosisPrevention • marking the tooth to be treated
Failure to remove all caries as well as weak and unsupported tooth structure Leads to contamination andre infection of the prepared rootcanal with saliva and bacteriaconducting to endodontic failure.Correction: According to the case, sometimesretreatment may be needed.Prevention: Careful remove of all caries andunsupported tooth structure.
Damage to existing restorationIn preparing an access cavity through a porcelainor porcelain-bounded crown, will sometimes chip.Correction: Minor porcelain chip can at timebe repaired by bounded composite resin to thecrown, however, the longevity of such repairsis unpredictable.Prevention: Placing a rubber dam clamp directlyon the margin of porcelain crown is preventing damage to the crownmargin and/or fracture of porcelain. The solution to prevent damage to an existing permanentlycemented crown is to remove it before treatment with little or nodamage to the crown.
Access cavity perforationsPeripherally through the side of the crown Floor of the chamber
Access cavity perforations, con’t Recognition Above the periodontal attachment The first sign of an accidental perforation will often be the presence of leakage: either saliva into the cavity 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 Correction 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 Materials usedCavit, amalgam, calcium hydroxide paste, SuperEBA, glass ionomer,gutta-percha, hemostatic Mineral trioxideagents. aggregate
Access cavity perforations, con’t Prognosis: Location of the perforation Time the perforation is open to contamination Ability to seal the perforation Prevention: Thorough examination of diagnostic preoperative radiographs Close 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
CROWN FRACTURE Causes: Preexisting infraction Recognition: By direct observation Treatment: Tooth Extraction Prevention: Reduce the occlusion before working length is establishedInfracted crown should be supported with circumferentialbands or temporary crowns
Instrumentation related mistakes-Ledge formation-Canal blockage-Cervical canal perforations-Midroot perforations-Apical perforations-Separated instruments and foreignobjects
LEDGE FORMATIONLedge is an internal transportation of the canalwhich prevents positioning of an instrument tothe apex in an otherwise patent canal.
Ledge formation, con’tCauses:- 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 filesize.
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 into the 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.
Separated Instruments and Foreign Objects :Instrument breakage is a common and frustratingproblem in endodontic treatment which occurs byimproper or overuse of instruments.
Separated Instruments and Foreign Objects con’t: 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 instrumentRadiographs showing broken instruments in different levels ofcurved 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.
root perforation Root perforations can be identified ascervical apical midroot
root perforation con’t These are usually caused by three errors: 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.
root perforation con’t Cervical perforationsThe cervical portion of the canal is most oftenperforated during the process of locating andwidening the canal orifice or inappropriateuse of gate-glidden burs.
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 cavity Magnification with either loupes, endoscope, or microscope is useful.
Cervical perforations con’t 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.
Midroot perforations-commonly occur in the carved canal when a ledg hasformed during instrumentation, or along inside thecurvature of root canal, as it straightened out, i.e.strip perforation.Recognition:-blood in the canal indicates that a perforation hasoccurred.Management:-MTA is the material of choice to close the perforation
Apical perforationsCauses :-1-The file not passing a curved canal2-not establishing accurate working length4-Over instrumentation.
Apical perforations, con’tDetection•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 asuspected apical perforation (bleeding at the tip ofpaper point)•Radiographically with the instrument inside.
Apical perforations, con’tTreatment:-•If the perforation create newforamen:•One is now dealing with twoforamina: one natural, the otherlateral. Obturation of both of theseforamina and of the main body ofthe canal requires the verticalcompacting techniques with heat-softened gutta-percha.
Apical perforations, con’tIf the perforation is caused by overinstrumentation:corrective treatment include-Re-establishing tooth length short of the original length and thenenlarging the canal with largerinstruments, to that length.-The canal is then cautiously filled to thatlength
Apical perforations, con’tCreating an apical barrier is anothertechnique that can be used to prevent overextensions during root canal filling. Materialsused for developing such barriers includecalcium hydroxide powder,hydroxyapatite, and , more recently,MTA.
OBTURATION-RELATED MISHAPSOver or underextended root canal fillings Causes:- over extended Under extended filling filling B-poorly A-Failure to prepared fit the master apical gutta-percha canal ,particularly in perforation point the apical part accurately. of the canal.
obturation-related mishaps con’t -Recognition of an inaccuracy placed root canal filling usually takes place when a post treatment radiograph is examined.
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.
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.
Irrigant-Related Mishaps con’t 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.