Fig. 1

The pre operative radiograph revealed the following – 

1. Missed palatal canal.

2. Buccal canal with very short obturation ( only till the middle third of the canal). 

3. Fractured restoration associated with the tooth.

4. Suspected ledge in buccal canal.

Fig. 2

The tooth was isolated & old restorative material  was removed. 

It was noted, that due to under extension of access cavity palatally, the canal was missed by previous operator.

Fig. 3

Old obturation material was removed from the canal, with the help of H files and rotary files used at a high speed.

A ledge was found in buccal canal at the point where previous obturation material had ended. It was bypassed with 10 number k file used in picking motion. 

Throughout the process, the canal was irrigated well with sodium hypochlorite after withdrawal of file from the canal each time.

Fig. 4

Access cavity was extended palatally. Palatal canal was found and negotiated with k file.

Fig. 5

Both the canals were negotiated till proper working length.

The working length was determined using an electronic apex locator and was confirmed on a radiograph.

Fig. 6

Coronal flaring was done and glide path was properly established.

The canals were shaped till 25-06% size till the working length.

Fig. 7

Thorough irrigation protocol was followed throughout the procedure which was as follows –


During shaping-

  1. 5.25% NaOCl used after each file use

After shaping –

  1. 5.25% NaOCl was introduced in the canal. It was heated within the canal using the down pack tip of obturation device and then was ultrasonically activated using Endo Ultra. This sequence was repeated 5 times per canal.
  2. Distilled water was used to flush the canals. 
  3. Canals were then irrigated with Bioakt and  the solution was activated ultrasonically.
  4. Canals were once more rinsed with distilled water.
Fig. 8

Microscopic image of shaped and cleaned canals and isthmus area. 

Fig. 9

The canals were then obturated using warm vertical compaction technique. The sealer used was AH plus.

Immediate post op – angulated view radiograph showed obturation of both the canals till the apex.

Fig. 10

Immediate post op – slightly angulated view.

Fig. 11

Post op x-ray image – straight angulation.

The patient was referred back to the referring dentist for post endodontic restorative work.

Fig. 12

Immediate post obturation image captured through a dental operative microscope.

Fig. 13

Three months follow up showed that patient was absolutely symptom free.


During a root canal treatment, understanding the root canal anatomy and usual location of canals is important in order to be able to locate them. Further, a good, undistorted pre-operative radiograph serves to be of high value in being able to locate all the canals. A proper access cavity preparation plays a vital role in localization of canals and also helps in  their easy instrumentation. Using magnification also aids in proper visualization of the tooth structures and canals.

While bypassing a ledge, the key is to not apply force and irrigate well from time to time. Also while negotiating a ledge, understanding the possible reasons for its creation is important.

During a root canal treatment, as well during endodontic retreatment procedures, a good irrigation protocol and using a combination of irrigating solutions in order to achieve proper cleansing and disinfection of the root canal system is important.


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