← Back

The Furcation Accessory Canal

Terry Pannkuk, DDS, MScDComplications: Advanced Management, Complications: Advanced Management, Calcification, Calcification, Endo-Perio Combined Lesions, Endo-Perio Combined Lesions, Recall Observations, Recall Observations, Sample Cases, Sample Cases, All by Date, All by Date


Preoperative periapical radiograph (10/2/2006)


Preoperative radiograph noting a subtle furcation radiolucency (arrow)


All fin and groove calcifications were removed


A very subtle microscopic accessory canal orifice was noted on the pulp chamber floor


Rinsing with alcohol and drying made it more noticeable


During obturation, gutta percha and sealer were compacted into the pulp chamber floor


After compaction a dot of root filling could be observed in the orifice


The pulp chamber and access prep was kept meticulously isolated, cleaned and sandblsted before filling with a bonded resin


Immediate post-operative periapical radiograph (11/1/2006)


Immediate post-operative periapical radiograph (11/1/2006, additional off-angle view)


Recall examination CBCT scan capture highlighting the mesial root (9/16/2020)


Recall examination CBCT scan capture highlighting the distal root (9/16/2020)


Recall periapical radiograph (16 years later) showing normal osseous structures (9/16/2020)


Recall radiograph with a horizontal angle showing uniform periodontal ligament space width into the furcation with the prior incipient radiolucency being absent and presumed healed (9/16/2020)

Prev 1 Next

Patient: 70 year-old female (time of treatment, 84 year-old at recall), history of breast cancer and managed hypertension, pacemaker (2018)

Chief Complaint: 10/2/2006: cold and biting sensitivity localized to the mandibular right first molar (#30)

Dental History: The patient presented with the said symptoms on 10/2/2006 after having a crown procedure started 3 months earlier, a temporary crown had been placed (#30).

Significant Findings (#30): Clinical examination revealed a 4mm periodontal pocket at the mesiolingual area, slight percussion sensitivity, and a sharp-transient response to cold thermal testing. The periapical and horizontal/bitewing radiographs demonstrated severe pulp chamber calcification, and an incipient furcation radiolucency.

Pulp and Periradicular Diagnosis (#30): Stressed pulp with calcific degeneration, acute periapical periodontitis.

Treatment Prognosis: Good

Treatment Plan: Nonsurgical Endodontic Therapy (#30)

Special Considerations of Performed Treatment:

Pulp capping resulting in pulp stimulation leads to dystrophic calcification of the pulp space as the most common sequela. Isolated areas of the pulp may contain vital tissue with pockets of walled off pulp degenerating and becoming necrotic. Furcation accessory canals have been reported to occur frequently in molar teeth leading to breakdown of adjacent osseous structures due to percolation of inflammatory mediators through these unanticipated portals of exit.

In this case an area of incipient furcation bone loss was noted. Access revealed an accessory canal on the pulp chamber floor (Figures 1 and 2). It is important to have immaculate rubber dam isolation which in this case was aided by sealing with Dycal. Also important is the complete elimination of dystrophic (tertiary) dentin. Calcifications were carefully dissected from the pulp chamber floor and from fin areas and connecting grooves (Figure 3). Once removed, the glistening dentine surface rinsed with 17% EDTA will show subtle orifices, grooves, and anomalies that otherwise would not be detectable if calcifications were not removed (Figures 4 and 5). A suspected furcation accessory canal was noted, cleaned and filled by compacting gutta pecha/sealer into the pulp chamber floor (Figure 6). A speck of gutta percha was noted to be sealing it after compaction and clearing away of excess root filling material (Figures 7 and 8). A resin bonded core was placed under strict aseptic rubber dam isolation and immediate post-treatment radiographs taken (Figures 9 and 10).

In summary, meticulous concern for all subtle root canal system anatomy is recommended to prevent periradicular attachment loss and bone loss that might be falsely attributed to a periodontal disease vector.

Key Learning Points:

  1. It is very important to eliminate all root canal system calcifications when performing root canal treatment. Failure to do so might lead to crypts of septic communicating debris inflaming and destroying the attachment apparatus.
  2. Aseptic isolation during core placement is of great importance and should be considered part of the root canal treatment preventing coronoapical leakage and delayed treatment failure.
  3. Furcation attachment/bone loss can often be attributed to an endodontic accessory canal vector.
  4. Long term recall follow-up of your own cases increases your knowledge of your own endodontic case outcome results.

Join the discussion

You must log in or create a free account to post a comment.