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Year : 2022  |  Volume : 11  |  Issue : 1  |  Page : 85-88

Mandibular permanent first molar with six conduits – A case report

Department of Pedodontics and Preventive Dentistry, Army College of Dental Sciences, Secunderabad, Telangana, India

Date of Submission10-Jun-2021
Date of Decision16-Jul-2021
Date of Acceptance28-Jul-2021
Date of Web Publication23-May-2022

Correspondence Address:
Dr. M Divya Banu
Department of Pediatric and Preventive Dentistry, Army College of Dental Sciences, Secunderabad - 500 087, Telangana
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jdrntruhs.jdrntruhs_74_21

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Success in the non-vital pulpal therapy in permanent teeth can be achieved after a complete and thorough cleaning and shaping of all the canals and achieving hermetic seal through restoration of those prepared canals. This clinical case describes the unusual morphological configuration of the root canals in the mandibular permanent first molar. This case report adds to the available literature on various anatomical variations in the root canal system of mandibular first molars and emphasizes the importance of dealing with rare morphological variations while performing pulpal therapies to have a successful outcome in them.

Keywords: Mandibular molars, middle distal canal, middle mesial canal, NiTi rotary files, root canal variations, six root canals

How to cite this article:
Krishna Murthy V V, Pusuluri S, Vellore KP, Banu M D. Mandibular permanent first molar with six conduits – A case report. J NTR Univ Health Sci 2022;11:85-8

How to cite this URL:
Krishna Murthy V V, Pusuluri S, Vellore KP, Banu M D. Mandibular permanent first molar with six conduits – A case report. J NTR Univ Health Sci [serial online] 2022 [cited 2023 Feb 7];11:85-8. Available from: https://www.jdrntruhs.org/text.asp?2022/11/1/85/345807

  Introduction Top

The goal of root canal treatment is thorough cleaning and three-dimensional filling.[1] Sufficient knowledge on the root canal morphology, good anticipation, and absolute clinical thoroughness are fundamental prerequisites for successful endodontic therapy.[2] A major cause of endodontic failure is the inability to locate canals and incomplete debridement of the root canal system.[3] The complexity of the root canal morphology, especially in posterior teeth, poses a challenge for precise diagnosis and successful outcome.[4] Mandibular first molar is considered to be the most common tooth involved in endodontic procedures because it is the earliest permanent multi-rooted tooth to erupt in the oral cavity.[5] As per conventional root canal morphology, mandibular first molars have two roots (mesial and distal); there are two canals in the mesial root (Mesiobuccal and Mesiolingual canals) and one or two canals in the distal root (Distal/Distobuccal and Distolingual canals).[6] Numerous studies have demonstrated wide anatomical variations in the mesial and distal roots of mandibular molars.[2],[7] The main variants in the mandibular molars are the presence of an extra third root, called radix, and the existence of extra root canals in the mesial or distal roots (Middle mesial canal and Middle distal canal). A knowledge of such variations and good diagnostic aids are crucial for successful endodontic management.[8]

  Case Report Top

A 15-year-old male patient with no significant medical history reported to the Department of Pedodontics with a chief complaint of pain in his lower right back tooth region while eating and lying down to sleep. Past dental history revealed that the patient visited a dentist earlier and started the treatment, but the symptoms persisted. On clinical examination, deep dentinal caries was seen on the lower permanent first molar with access opening done and opened cavity into the pulp chamber. On radiographic examination, radiolucency from the occlusal surface into the coronal chamber and conventional root morphology was seen. As per the clinical and radiographic interpretation, the tooth was diagnosed with chronic irreversible pulpitis, and hence root canal treatment was planned.

Local anesthesia with epinephrine was introduced through the inferior alveolar nerve and a rubber dam was placed for isolation. After removing the debris with a spoon excavator, the pulpal floor was carefully examined with an odontoscope. The Mesiobuccal (MB) and Mesiolingual (ML) canal, and distobuccal (DB) and distolingual (DL) canal orifices were identified. The Middle mesial (ML) canal and Middle distal (MD) canal were detected by careful exploration of the developmental grooves [Figure 1]. Working length was determined under conventional RVG and it also showed that all six canals were independent. (Vertucci's classification VIII 3-3) [Figure 2]. The canals were negotiated and patency was achieved with #10 K file (Mani, Inc.). Then hand instrumentation was done till # 20 k file (Mani, Inc.) followed by Rotary instrumentation with ProTaper Gold rotary NiTi instruments (Dentsply, Maillefer) in a brushing motion. Cleaning and shaping were done till F2 in mesial and distal canals. Irrigation and lubrication were performed with 3% sodium hypochlorite and EDTA, respectively, and subsequently flushed with sterile saline. Calcium hydroxide dressing was given for 10 days. It was removed with saline irrigation. Canals were dried using paper points, and master cone radiograph was taken to confirm [Figure 3]a and [Figure 3]b. Following this, obturation was performed. ProTaper guttapercha cones (Dentsply) corresponding to F2 size were coated with MTA sealer (Fillapex Angelus) and placed in the canal and sealed. The post-operative radiograph was taken to assess the quality of obturation and post-endodontic composite restoration [Figure 4].
Figure 1: Tooth #46 showing six orifices (MB- Mesiobuccal, MM- Middle mesial, ML- Mesiolingual, DB- Distobuccal, MD- Middle distal, DL- Distolingual)

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Figure 2: Working length determination

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Figure 3: (a) An RVG showing master cones in the three distal canals. (b) An RVG showing master cones in the three mesial canals

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Figure 4: Post-obturation RVG showing post-endodontic restoration with composite

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  Discussion Top

The mandibular first molar is the earliest permanent tooth to erupt into the oral cavity. It is the most heavily restored tooth and common to undergo root canal treatment.[5] It also has a lower success rate because of inadequate treatment of root canal system, incomplete elimination of microorganisms and remnants of the pulp tissues, as well as complicated morphology of its root canal system.[9] Tagger et al.[10] suggests that clinicians should always suspect and strive to explore the canals, whenever the instrument showcases an aberrant deviation from the center on deeper penetration.

The presence of two canals in the mesial root and one in the distal root of mandibular molars is 65%, and that of two canals in the distal root is 30%. The presence of the middle mesial canal has been reported to vary between 1% and 15%, and the middle distal canal in the mandibular first molar to vary between 0.2% and 3%.[11] According to J. Kottoor, in the Indian and Turkish population, it was found to be 1.7%, 1.6% in the Thai community, whereas in Burmese it was noted as 0.7% and 0.2% among Senegalese.[8]

The current case is a rare configuration in the mandibular first molar with three distinct mesial and distal canals. Pre-operative radiograph helped in the location and confirmation of the roots and canals along with their paths and divulged the presence of two roots and six canals. The MB, ML, DB, DL, MM, and MD were located by application of basic concepts.[6] In addition, staining the pulp chamber with 1% methylene blue dye or performing the sodium hypochlorite “champagne bubble” test and visualizing the root canal's bleeding points may also be used to locate extra canals. Based on the discussion above, it appears that better diagnostic aids and knowledge are very essential to manage various possible morphological variations in mandibular first molars to achieve good results.

  Conclusions Top

This case report discusses the endodontic management of a mandibular permanent first molar with two roots and six canals, and also highlights the role of the clinician in having good anticipation of possible morphological variations in root canal systems of mandibular first molars, which will help to reduce endodontic failures caused by incomplete root canal preparation and obturation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.


The authors would like to thank Dr.Shilpa G, Reader, Dr.Santoshkumar CH, Reader, and Dr.Mayuri Ganesh, Senior lecturer, Department of Pedodontics and Preventive Dentistry, Army College of Dental Sciences.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Cohen S, Hargreaves KM. Pathways of Pulp. 9th ed. Rio de Janeiro: Mosby Elsevier; 2007.  Back to cited text no. 1
Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endod Top 2005;10:3-29.  Back to cited text no. 2
Nair PN. On the causes of persistent apical periodontitis: A review. Int Endod J 2006;39:249-81.  Back to cited text no. 3
de Pablo OV, Estevez R, Peix Sanchez M, Heilborn C, Cohenca N. Root anatomy and canal configuration of the permanent mandibular first molar: A systematic review. J Endod 2010;36:1919-31.  Back to cited text no. 4
Vertucci JF, Haddix EJ, Britto RL. Tooth morphology and access cavity preparation. In: Cohen S, Hargreaves MK, editors. Pathways of the Pulp. 9th ed. St Louis, MO: Mosby, Inc.; 2006. p. 220.  Back to cited text no. 5
Sreenath N, Mithra N Hegde. Endodontic management of mandibular first molar having six root canals – a case report. Int J Contemp Med Res 2018;5:I13-5.  Back to cited text no. 6
Ahmed HM, Luddin N. Accessory mesial roots and root canals in mandibular molar teeth: Case reports, SEM analysis and literature review. Endod Pract Today 2012;6:195-205.  Back to cited text no. 7
Kottoor J, Sudha R, Velmurugan N. Middle distal canal of the mandibular first molar: A case report and literature review. Int Endod J 2010;43:714-22.  Back to cited text no. 8
Friedman S. Prognosis of initial endodontic therapy. Endod Top 2002;2:59-88.  Back to cited text no. 9
Tagger M, Tamse A, Katz A, Korzen BH. Evaluation of the apical seal produced by a hybrid root canal filling method, combining lateral condensation and thermatic compaction. J Endod 1984;10:299-303.  Back to cited text no. 10
Reuben J, Velmurugan N, Kandaswamy D. The evaluation of root canal morphology of the mandibular first molar in an Indian population using spiral computed tomography scan: An in vitro study. J Endod 2008;34:212-5.  Back to cited text no. 11


  [Figure 1], [Figure 2], [Figure 3], [Figure 4]


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