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 Table of Contents  
Year : 2022  |  Volume : 19  |  Issue : 3  |  Page : 169-171

Root canal therapy of maxillary first molar with seven canals diagnosed using cone beam computed tomography – a case report

1 Department of Conservative Dentistry and Endodontics, SGPGI, Lucknow, Uttar Pradesh, India
2 Department of Nuclear Medicine, SGPGI, Lucknow, Uttar Pradesh, India

Date of Submission29-Jan-2022
Date of Decision09-May-2022
Date of Acceptance24-May-2022
Date of Web Publication14-Sep-2022

Correspondence Address:
Saini Rashmi
BDS, MDS, Block.12, MRA92A, SGPGI, Lucknow, Uttar Pradesh
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/tdj.tdj_3_22

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For successful clinical outcomes in endodontics, a thorough knowledge of root canal morphology, adequate clinical and radiographic assessment, and the use of newer diagnostic aids are required. This case report describes the diagnosis and endodontic management of a three-rooted left maxillary first molar which had three roots and seven canals (MB1, MB2, MB3, DB1, DB2, MP, and DP). This unusual morphology of the maxillary first molar was confirmed using a cone-beam computed tomography scan. This article discusses the morphology of the maxillary first molar and how to successfully diagnose and negotiate the extra canals using the most up-to-date techniques.

Keywords: cone-beam computed tomography, maxillary molars, unusual morphology

How to cite this article:
Rashmi S, Kumar SV. Root canal therapy of maxillary first molar with seven canals diagnosed using cone beam computed tomography – a case report. Tanta Dent J 2022;19:169-71

How to cite this URL:
Rashmi S, Kumar SV. Root canal therapy of maxillary first molar with seven canals diagnosed using cone beam computed tomography – a case report. Tanta Dent J [serial online] 2022 [cited 2023 Jan 30];19:169-71. Available from: http://www.tmj.eg.net/text.asp?2022/19/3/169/356084

  Introduction Top

For successful root canal therapy, a thorough understanding of the complexities of root canal systems is required. Even though various authors have exhaustively described the morphology of the permanent maxillary first molar, which most often has three roots and three canals. The number of canals can vary, with the second mesiobuccal canal being the most common variant, ranging from 18 to 96.1% [1],[2] The incidence of two canals in the distobuccal root has been reported by a few authors to be between 1.9 and 4.30% [3]. In a few other studies, maxillary molars with palatal roots were found to have two canals in 2–5.1% of cases [4],[5]. Conversely, maxillary first molars with more than six canals are uncommon, with only a few occurrences recorded in the endodontic literature [6]. This case report discusses the effective root canal therapy of a maxillary first molar with three roots and seven root canals (MB1, MB2, MB3, DB1, DB2, MP, and DP). Cone-beam computed tomography (CBCT) was used to validate our findings.

  Case report Top

A 25-year-old male patient presented to the department of conservative dentistry and endodontics with the chief complaint of pain and sensitivity in his left upper back region of the jaw for 15 days. Clinically, the tooth had a carious lesion on the distoocclusal surface of left maxillary first molar and it was tender to percussion. An intense lingering pain was generated by sensitivity testing of the affected tooth with heated gutta-percha (Dentsply Maillefer, Switzerland) and Endo Ice (Coltene/Whaledent GmbH+ Co. KG, Langenau, Germany). A distoocclusal radiolucency approaching the pulp space with expanded periodontal ligament space in respect to the distobuccal root was observed on a conventional intraoral periapical radiograph [Figure 1]a. A provisional diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis was made based on clinical and radiographic evidence. The patient was made aware of the clinical situation, and nonsurgical endodontic treatment was scheduled.
Figure 1: (a) Preoperative radiograph of the left maxillary molar, (b) clinical view of access cavity preparation showing canal orifices, (c) working length determination, (d) mastercone radiograph, (e and f) postobturation radiograph and cinical view.

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After rubber dam isolation, the tooth was anesthetized with 1.8 ml (30 mg) 2% lignocaine containing 1: 2002000 epinephrine (Xylocaine; AstraZeneca Pharma India Ltd). Endodontic access cavity preparation was done using high-speed diamond round and Endo-Z burs (Dentsply Maillefer, Konstanz, Germany) [Figure 1]b. The pulp chamber was irrigated with 3% NaOCl to remove the coronal pulp tissues. Clinical examination with a DG 16 endodontic explorer (Hu Friedy, Chicago, Illinois, USA) revealed three canal openings (MB1, MB2, MB3) in the mesiobuccal root, two (DB1 and DB2) in the distobuccal root, and two (MP and DP) in the palatal root. The working length was determined with the help of an apex locator (Root ZX; Morita, Japan) and later confirmed using an intraoral periapical radiograph [Figure 1]c. Because intraoral periapical radiographs are 2D images of 3D objects, it was decided to do CBCT imaging of the tooth to validate this atypical morphology. After that CBCT scan of the maxilla was performed. The CBCT images in various views revealed seven canals (three mesiobuccal, two palatal, and two distobuccal) in the left maxillary first molar [Figure 2]a and [Figure 2]b.
Figure 2: (a) Preoperative cone beam computed tomography (CBCT) axial section of maxillary arch showing seven canal orifices of tooth 26. (b) CBCT axial section of maxillary arch at coronal, cervival, mid-root, and apical level of tooth 26. (c and d). Postobturation CBCT axial and saggital view of left maxillary molar.

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As the patient was asymptomatic at the second appointment, further treatment was continued and the tooth was anesthetized followed by rubber dam isolation. Cleaning and shaping were done using ProTaper nickel titanium rotary instruments (Dentsply Maillefer) using the crown-down technique. Individually, the MB1, MB2, MB3, DB1, and DB2 canals were prepared till the F2 file of the ProTaper rotary system. The MP and DP canals were prepared separately until the F3 file of the ProTaper rotary system. During cleaning and shaping, copious irrigation was performed with 3% NaOCl, normal saline, 17% ethylenediaminetetraacetic acid, 2% chlorhexidine digluconate was used as the final irrigant. The canals were dried with absorbent points (Dentsply Maillefer) followed by obturation using cold lateral compaction of gutta-percha (Dentsply Maillefer) and AH Plus resin sealer (Maillefer, Dentsply) [Figure 1]d, [Figure 1]e, [Figure 1]f. After obturation a postoperative CBCT scan was done [Figure 2]c and [Figure 2]d. A posterior composite resin core was then used to repair the tooth and advised the patient for a porcelain crown. After 3 months, the patient's follow-up revealed no signs or complaints related to the restored tooth.

  Discussion Top

This case report describes a left maxillary first molar with three mesiobuccal (MB1, MB2, and MB3), two distobuccal (DB1 and DB2), and two palatal (MP and DP) canals. The shape of root canals, particularly in multirooted teeth, presents a continuing challenge for successful endodontic therapy. Endodontic diagnosis and management of these complexities are difficult, and failure to identify and treat these extra canals might have a severe impact on treatment outcomes [7]. Because periapical radiographs are compressed two-dimensional images of a three-dimensional object, the quantity of information received from them is limited, which could explain why the radiographic study of the tooth revealed no abnormalities in the canal structure.

In this present case, CBCT imaging was used to confirm the extra canals as it shows the dental structures in a three-dimensional view, as well as it offers clear structural images with high contrast. Of the various comprehensive maxillary first molar ex vivo studies in the dental literature, only Baratto Filho et al.[8] published a maxillary first molar with three roots and seven root canals. Only one tooth out of 140 extracted maxillary first molars had seven root canals, including three MB, three DB, and one palatal canal. The frequency of MB2 canals in the MB root was reported to be 92.85, 95.63, and 95.45% in ex vivo, clinical and CBCT studies, respectively, whereas the corresponding figures for the DB root (DB2) were 1.15 and 3.75% in ex vivo and clinical studies, and the palatal root (second palatal canal) were 2.05, 0.62, and 4.55% in ex vivo, clinical and CBCT studies respectively.

IOPA radiographs are commonly used to analyze root canal shape before, during, and after endodontic therapy. However, because these radiographs have limits, newer diagnostic methods such as CBCT scanning have lately been adopted, primarily in cases where atypical root canal morphology is suspected [9]. With the use of CBCT, we were able to confirms seven separate root canal orifices (MB1, MB2, MB3, DB1, DB2, MP, and DP) in this patient.

In this current case, we choose to employ single cone obturation technique, as it is a straight forward approach that matches the geometry of nickel-titanium instrumentation systems allows gutta-percha to adapt well to canal walls, leaving just a small gap between gutta-percha and canal wall that is filled with root canal sealer. Several studies comparing the single-cone technique to different root canal filling procedures found that the sealing ability and leakage at the coronal and apical areas were similar [10].

To examine the apical sealing, condensation, and containment of the root canal filling material inside the root canal system, a postobturation radiography evaluation is required shortly after root canal obturation. As a result, a postobturation CBCT scan was done in this case, which aided in the evaluation of the root canal fillings' integrity.

CBCT imaging was found to be the most important factor in the effective care of a tooth with complex internal architecture and seven root canals. As a result, we recommend that Endodontists become more familiar with the use of dental microscopy and novel imaging techniques such as CBCT scanning to improve success rates, particularly in teeth with complicated architecture.

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 name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflcits of interest.

  References Top

Rodrigues E, Braitt AH, Galvão BF, da Silva EJ. Maxillary first molar with 7 root canals diagnosed using cone-beam computed tomography. Restor Dent Endod 2017; 42:60–64.  Back to cited text no. 1
Sharma S, Mittal M, Passi D, Grover S. Management of a maxillary first molar having atypical anatomy of two roots diagnosed using cone beam computed tomography. J Conserv Dent 2015; 18:342–345.  Back to cited text no. 2
Thomas RP, Moule AJ, Bryant R. Root canal morphology of maxillary permanent first molar teeth at various ages. Int Endod J 1993; 26:257–267.  Back to cited text no. 3
Alenazy MS, Ahmad IA. Double palatal roots in maxillary second molars: a case report and literature review. Saudi Endod J 2015; 5:56–60.  Back to cited text no. 4
  [Full text]  
Bhargav K, Ravichandra R, Jyothi M, Charan Teja GV. Management of anatomical aberrations in maxillary first molars. Int J Contemp Med Res 2017; 4:387–389.  Back to cited text no. 5
Martins JN. Endodontic treatment of a maxillary first molar with seven root canals confirmed with cone beam computer tomography – case report. J Clin Diagn Res 2014; 8:ZD13-5.  Back to cited text no. 6
Jain D, Reddy S, Vanigalla BS, Kamishetty S. Endodontic management of a mandibular first molar with six root canal systems. J Conserv Dent 2015; 18:419–422.  Back to cited text no. 7
[PUBMED]  [Full text]  
Baratto Filho F, Zaitter S, Haragushiku GA, de Campos EA, Abuabara A, Correr GM. Analysis of the internal anatomy of maxillary first molars by using different methods. J Endod 2009; 35:337–342.  Back to cited text no. 8
Kottoor J, Hemamalathi S, Sudha R, Velmurugan N. Maxillary second molar with 5 roots and 5 canals evaluated using cone beam computerized tomography: a case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109:e162–e165.  Back to cited text no. 9
Wu MK, van der Sluis LW, Wesselink PR. A 1-year follow-up study on leakage of single-cone fillings with RoekoRSA sealer. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006; 101:662–667.  Back to cited text no. 10


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