Discovery of a Second Palatal Canal in a Maxillary Second Molar

Patient: 81 year-old female in extraordinarily good health

Chief Complaint: cold and hot sensitivity

Dental History: The patient’s dentist began caries control on the maxillary right second molar which resulted in a pulp exposure. The patient was experience mild symptoms and was referred for endodontic treatment. The patient had a history of recurrent caries.

Significant Findings (#2): Clinical examination normal periodontal probing depths but with subgingival caries at the mesial aspect. Percussion elicited a moderately painful response and cold thermal stimulation resulted in sharp lingering discomfort.

Pulp and Periradicular Diagnosis (#2): early stage acute pulpitis with acute periradicular periodontitis.

Treatment Prognosis: Fair (#2)

Treatment Plan: NSRCT (#2) with minor crown-lengthening.

Special Considerations of Performed Treatment:
Access was difficult due to the distal tooth position, and limited opening, and routine endodontic treatment was anticipated. Isolation with a rubber dam was somewhat challenging due to the mesial caries but aseptic control was achieved.

The sequence of treatment steps were as follows:

First Treatment Visit (11/5/2020)

1. Caries control was performed and the pulp chamber was accessed. The 3 main canals (MB,DB and P) were found uneventfully, but an unusual bleeding point was noted at the ML line angle. Further access extension revealed a second palatal canal system with a separate root.

2. The ML area was sealed off with Dycal and the second palatal (P2) canal was cleaned shaped and filled at this visit. A deep Cavit temporary filling seal was placed into the orifice so that subsequent continuation of treatment would be simplified. After placement of a copper band.

3. The MB, DB and P1 canals were cleaned shaped and filled with calcium hydroxide. A Cavit temporary filling was placed without a spacer and the patient was scheduled for a second visit one week later.

4. A CBCT scan was taken to verify the unusual anatomy.

Second Treatment Visit (11/12/2020)

1. A copper band was fit and cemented with Duralon cement prior to access.

2. The remaining canals were cleaned shaped and obturated via the vertical compaction of warmed gutta percha technique. A short third visit was scheduled to place a bonded amalgam core.

Third Treatment Visit (11/19/2020)

An amalgam core was placed and the patient was referred back to her restorative dentist.

Key Learning Points:

1. Direct line access is essential so that anomalous anatomy can be discovered and properly treated.

2. Aseptic isolation and control of the treatment field is essential for predictable long term endodontic success.

3. Placement of a band facilitates the creation of a reservoir so that an appropriate volume of irrigant can be used to debride the root canal system during cleaning and shaping.

4. An amalgam core provides unique strength properties and long-term structural integrity.