Dr. Kenneth Serota|Dr. Hugh Maguire|Dr. Steven J. Cohen|Dr. Francesco Maggiore
Dr. Steven J. Cohen, DDS, Cert Endo
Mississauga, Ontario, Canada
A 45 year old male, in good health, referred for treatment of tooth 3.7. Referral letter specifies the broken instrument in the mesio-lingual canal. Patient was referred as an "emergency" with local anesthesia wearing off in the 3rd quadrant. Clinical examination revealed this tooth is lingually inclined. Note the following details on the Preoperative radiograph:
- Length and location of the fragment - below the curve in the apical half of the canal.
- Canal space altered by attempted removal by the clinician.
- Ledge of dentin at the mesial canal orifice - chamber level
- Ledge of dentin at the occlusal surface - restrictive access design.
Step One: Consultation with the patient, review the problem, and possible treatment options. Confirm that the patient wants to proceed, knowing it may take multiple visits to complete, and that the file may not be retrieved. Discuss complications, perforations, and failure. Apical surgery unlikely in the area of 3.7...
Step Two:
Correct the access cavity, and locate fragment. Apply ultrasonic energy, alternating between 2 tips:
CPR-8: long and thin; light energy transmitted to file
CPR-5D: diamond coating selectively removes dentin around the file; when file shows movement, this tip can "bounce" it out of position
Check film to confirm lengths:
NOTE: distortion of the canal space at level of the instrument - once the file was removed, pinpoint perforation noted at outer root wall, in ML canal
Correct the access cavity, and locate fragment. Apply ultrasonic energy, alternating between 2 tips:
CPR-8: long and thin; light energy transmitted to file
CPR-5D: diamond coating selectively removes dentin around the file; when file shows movement, this tip can "bounce" it out of position
Check film to confirm lengths:
NOTE: distortion of the canal space at level of the instrument - once the file was removed, pinpoint perforation noted at outer root wall, in ML canal
Canal spaces are cleaned and shaped, but now we have perforation to contend with as well. How do we fill apical to the perforation, without extruding material into the perf. site? If we seal the perforation first, how do we keep that material out of the apical third canal spaces?
Step Three:
The distal canal was obturated in the usual fashion. A new 25 gauge needle tip (Spartan/Obtura) was placed, to see if it could be custom curved to bypass the perf. site, to inject thermoplastic gutta percha in the apical third. This thinner gauge needle could bypass the perf., so the apical third of the MB and ML canals were obturated. Check film taken:
The distal canal was obturated in the usual fashion. A new 25 gauge needle tip (Spartan/Obtura) was placed, to see if it could be custom curved to bypass the perf. site, to inject thermoplastic gutta percha in the apical third. This thinner gauge needle could bypass the perf., so the apical third of the MB and ML canals were obturated. Check film taken:
Step Four:
Obturation done, to a level just apical to the perforation site. Collacote wound dressing packed into small perf site, as a matrix. MTA mixed, placed in ML canal space and packed down to close off the location of the perf. Canal spaces back-filled with injected gutta percha. Temporary restoration placed for closure. Recall in 3 months, will advise to proceed with crown if problems resolved.
Obturation done, to a level just apical to the perforation site. Collacote wound dressing packed into small perf site, as a matrix. MTA mixed, placed in ML canal space and packed down to close off the location of the perf. Canal spaces back-filled with injected gutta percha. Temporary restoration placed for closure. Recall in 3 months, will advise to proceed with crown if problems resolved.
