Fig. 1

A 58 years old female was referred for Endodontic Assessment of 46. The patient had  pain on biting and sensitivity to cold. Upon clinical examination the 46 had large amalgam restoration, was very tender to percussion and responded with discomfort on thermal stimuli. No perio pockets or mobility  was detected. Patient was informed of possible crack under restoration and questionable prognosis. She was under bisphosphonate treatment, and she wanted to avoid loss of tooth at any cost. A decision to perform endodontic treatment of tooth 46 was made and patient understood that prognosis was questionable.

Pre-op xray reveals sclerotic canals and the presence of Radix is noted. Pulp chamber also looks obliterated indicating presence of pulp stone.

Careful examination and assessment of the pre-op radiographs its essential for the management and outcome of the endodontic treatment.

Fig. 2

Pre-operative photo of tooth 46 revealing large amalgam restoration and buccal composite. Patient was informed of possible crack under amalgam restoration and questionable prognosis of tooth.

Fig. 3

Removal of amalgam restoration and deroofing pulp chamber with ultrasonics under microscope and noticing the MM canal.

Fig. 4

Working Length determination. The canals were scouted with 08k and 10k stainless –steel hand files. To determine  the working length an electronic apex locator was also used. The mesial canals were very sclerotic, and use of D-finders hand files were used to established patency.

The MM canal anatomy was confluent with MB canal. It originated as a separate orifice but apically joined the MB canal.

Achieving apical patency on MMC with D-finder file.

D-finders are almost 50% stiffer compared to conventional K-files.

This property improves the penetration force which is needed to prepare glide path of root canals which are narrowed by calcification.

Copious irrigation with 5,25% sodium hypochlorite and throughout the endodontic treatment.

Irrigation protocol included irrigation with 5,25% Noocl, 17% EDTA and activation of irrigants with the use of Ultra-X


Fig. 5

All the canals were shaped with Hyflex EDM 15/03, 10/05, 20/05 and 25 One File ( Coltene).

Notice the crack on the distal wall. 

Patient was informed about its presence and the questionable prognosis of the tooth.

Patient was on Bisphosphonate treatment and did not want to lose the tooth due to risk of osteonecrosis, but she was realistic about her expectations and decided to proceed with the Endodontic treatment of the tooth despite the questionable prognosis.

Placement of AH-plus Bioceramic sealer on Radix Entomolaris canal and Modified Warm vertical compaction using Fast Pack (Eighteeth).

Fig. 6

Obturation done with AH-plus Bioceramic sealer ( Dentsply) and modified Warm Vertical Compaction.

Fig. 7

Final X-ray of tooth 46.

The MM is converging with MB canal at the apical 1/3.

Access cavity was restored with composite resin and patient was referred back  to her dentist for an indirect cast restoration.

Fig. 8

Final X-ray of tooth 46.

Mesial shift

Fig. 9

Final X-ray of tooth 46.

Distal shift

Fig. 10

Before and after obturation of tooth 46.

Fig. 11

About  the author:  Andreas Louloudiadis

DMD 2001 University of Alabama USA

PGDip in Endodontics 2005 Aristotle University Greece

MSc in Advanced Endodontics 2023 Siena Italy

Certified Member of European Endodontic Society

Member of British Endodontic Society

Member of Hellenic Association of Endodontists

Fellow of SIE


Clinicians should be aware of the unusual anatomical features and variations in the mandibular first molars. A detailed knowledge of the pulp canal anatomy, multiple angulated radiograph and close inspection of the chamber floor at higher magnification with the help of operating microscope is key to locating and treating unusual anatomy.

Variations of anatomy do exist more often than we think, so as long as we have the knowledge, the right armamentarium and good clinical skills we can prepare, clean, disinfect and obturate  any of them efficiently and successfully.


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