Fig. 1

A 35 years old female was referred for retreatment of tooth 44, which was symptomatic. The initial x-ray revealed a periapical lesion around root in the presence of a poor endodontic therapy, as shown in figure .

Fig. 2

 A- insertion of a #10 K-file in the main buccal canal and glide path to full length to achieve patency 

B- insertion of another manual file in the second buccal canal, confirming another buccal split

C- an attempt to negotiate the lingual split to gain glide path while 2 files in buccals .

D- reaching full length in lingual split .

Fig. 3

A- x-ray shows entire removal of old gutta percha

B- cone fit in the buccal canal

C- cone fit in the lingual split

D- cone fit in all canals

Fig. 4

Summary of the steps of the retreatment, starting from the radiographic interpretation and ending up with obturation.

Fig. 5

Intra oral Microscopic photos show conservative access before and after obturation .

Fig. 6

The final x-ray shows the obturation of three canals followed by good coronal seal. The tooth is planned to be crowned soon.


Mandibular premolars can present a complex root canal morphology, which if not considered during the diagnosis and treatment, may lead to post-treatment complications or failure.

Use of an operating microscope or loop can promote the visualization of the pulp chamber and extra canal orifices. 

Therefore, the understanding of abnormal anatomy and variations is necessary to guarantee predictable result and successful treatment.


Vertucci FJ. Root canal morphology of mandibular premolars. J Am Dent Assoc 


Cleghorn BM, Christie WH, Dong CC. The root and root canal morphology of the human mandibular first premolar: a literature review. J Endod. 2007 May;33(5):509-16 

J. Kottoor, D. Albuquerque, N. Velmurugan, and J. Kuruvilla, “Root anatomy and root canal configuration of human permanent mandibular premolars: a systematic review,” Anatomy Research International, vol. 2013, Article ID 254250, 14 pages, 2013. 

Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58:589 –99. 

Rhodes JS. A case of unusual anatomy: a mandibular second premolar with four canals. Int Endod J 2001;34:645– 8. 15. D 

England MC Jr, Hartwell GR, Lance JR. Detection and treatment of multiple canals in mandibular premolars. J Endod 1991;17:174 – 8. 

Nallapati S. Three canal mandibular first and second premolars: a treatment approach. J Endod. 2005 Jun;31(6):474-6.