Saudi Endodontic Journal

: 2012  |  Volume : 2  |  Issue : 2  |  Page : 100--103

Endodontic management of maxillary second molar with a single root and a single canal diagnosed with cone-beam computed tomography scanning

Puneet Ahuja, Suma Ballal, Natanasabapathy Velmurugan 
 Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi Academy of Higher Education and Research (MAHER), Maduravoyal, Chennai, Tamil Nadu, India

Correspondence Address:
Puneet Ahuja
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi Academy of Higher Education and Research (MAHER), Alapakkam Main Road, Maduravoyal, Chennai - 600 095, Tamil Nadu


Root canal treatment of maxillary molars presenting with complex root canal configurations can be diagnostically challenging. The present case describes the endodontic management of a maxillary second molar with a single root and a single canal. The clinical detection of the single canal was made using a surgical operating microscope and confirmed using cone-beam computed tomography scanning.

How to cite this article:
Ahuja P, Ballal S, Velmurugan N. Endodontic management of maxillary second molar with a single root and a single canal diagnosed with cone-beam computed tomography scanning.Saudi Endod J 2012;2:100-103

How to cite this URL:
Ahuja P, Ballal S, Velmurugan N. Endodontic management of maxillary second molar with a single root and a single canal diagnosed with cone-beam computed tomography scanning. Saudi Endod J [serial online] 2012 [cited 2021 Dec 7 ];2:100-103
Available from:

Full Text


The complexity and diversity of root canal morphology, particularly in multi-rooted teeth, are constant challenges for diagnosis and successful endodontic therapy. [1] Thus, it is necessary for the clinician to have a knowledge of root canal anatomy and its variations. [2] The maxillary second molar usually presents with 3 roots: 1 palatal, 1 mesiobuccal, and 1 distobuccal, each with a single canal. [3] But Slowey emphasized that root canal morphology was limitless in its variability and that clinicians must be aware of the anatomic variations which constitute a formidable challenge to endodontic success. [4]

Variations in root and root canal anatomy of maxillary second molar have been observed earlier. Cases of maxillary second molar with two palatal roots, [5],[6] four roots, [3] three buccal roots [7] and five roots with five canals [8] have been previously reported in literature. Variations have also been reported in the form of fewer or lesser number of canals. [9],[10]

Conventional radiographs are routinely used to assess root canal anatomy, but these radiographs are only a two-dimensional image of a three-dimensional object resulting in superimposition of images. Recently developed cone-beam computed tomography (CBCT) for the preoperative assessment of unusual root canal morphology aids in the correct endodontic management of complex and challenging cases. [8],[11] The purpose of the present article is to report the endodontic management of a maxillary second molar with a single root and a single canal confirmed with the aid of dental operating microscope and CBCT examination.

 Case Report

A 37-year-old Indian male presented to the Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College, Chennai, India with the chief complaint of spontaneous toothache in his left posterior maxilla for 2 days. The pain intensified by thermal stimuli and on mastication. History revealed intermittent pain in the same tooth with hot and cold stimuli for the past 1 month. The patient's medical history was non contributory. A clinical examination revealed a carious maxillary left second molar with previously existing amalgam restoration occlusally, and was tender to percussion. The tooth was not mobile and periodontal probing around the tooth was within physiological limits. Vitality testing of the involved tooth with heated gutta-percha (Dentsply Maillefer, Ballaigues, Switzerland) and dry ice (R C Ice; Prime Dental Products Pvt. Ltd, Mumbai, India) caused an intense lingering pain, whereas electronic pulp stimulation (Parkel Electronics Division, Farmingdale, NY) caused a premature response. A preoperative radiograph revealed a coronal disto-occlusal radiolucency approaching the pulp space [Figure 1]. The radiograph did not clearly show the wide periodontal ligament space or the loss of lamina dura.{Figure 1}

From the clinical and radiographic findings, a diagnosis of symptomatic irreversible pulpitis with symptomatic apical periodontitis was made and endodontic treatment was suggested to the patient. The tooth was anesthetized with 1.8 mL (30 mg) 2% lignocaine containing 1:200,000 epinephrines (Xylocaine; AstraZeneca Pharma Ind Ltd, Bangalore, India.) followed by rubber dam isolation. On access opening, a single wide canal was located at the centre of the pulpal floor. Examination under a surgical operating microscope (Seiler Revelation, St. Louis, MO, USA) revealed the presence of only one single canal and no other canal orifices [Figure 2]. The working length was determined with the help of an apex locator (Root ZX; Morita, Tokyo, Japan) and later confirmed using a radiograph. Multiple working length radiographs were taken at different angulations [Figure 3].{Figure 2}{Figure 3}

To confirm this unusual morphology, it was decided to perform CBCT imaging of the tooth. Access cavity was sealed with IRM cement (Dentsply De Trey GmbH, Konstanz, Germany). An informed consent was obtained from the patient, and a multislice CBCT scan of the maxilla was performed (Simulix Evolution; Nucletron, Chennai, India Pvt. Ltd) with a tube voltage of 100 KV and a tube current of 8 mA. The involved tooth was focused, and the morphology was obtained in transverse, axial, and sagittal sections of 0.5-mm thickness. CBCT scan slices also confirmed a single root and a single canal with single portal of exit.

Cleaning and shaping was done using crown-down technique with ISO hand files and ProTaper nickel-titanium rotary instruments (Dentsply Maillefer). Irrigation was performed using normal saline, 2.5% sodium hypochlorite solution, with 17% ethylenediaminetetraacetic acid being used as the final irrigant. The canals were dried with absorbent points (Dentsply Maillefer), and obturation was performed using cold lateral compaction of gutta-percha (Dentsply Maillefer) with AH Plus resin sealer (Maillefer, Dentsply, Konstanz, Germany). The tooth was then restored with a posterior composite resin core (P60; 3M Dental Products, St Paul, MN). A postoperative radiograph [Figure 4] was taken and the patient was asymptomatic during the follow-up period.{Figure 4}


Morphologic variations such as the existence of maxillary second molars with a single root and a single canal system occur less frequently. A literature search revealed the incidence to be 0.5-3.1% [3],[12],[13] in the various in vivo studies, but Carlsen et al. [14] in an in vitro study from Denmark population (sample size of 104 teeth) reported the incidence of 30.4%. Recently, study of root and canal morphology of maxillary second molars in an Indian population revealed 0.9% of teeth with single roots but none with single root canal. [15]

Common iatrogenic access opening errors are caused during the search for missing canals. These errors include perforations and excessive tooth removal. Such iatrogenic errors can be minimized if the clinician has the knowledge of the general location and dimensions of the pulp chamber. Clinician should be aware of the variations in root canal anatomy, which can also occur in the form of lesser/fewer number of canals. The varying morphology of the root canals is normally ascertained with radiographs of different angulations or careful examination of the floor of the pulp chamber. This gives us a clue to the type of canal configuration present. This case report is one such case wherein we suspected missed canals initially but ended finding only one single canal.

Usually canal variations in such cases occur bilaterally. Fava et al. [9] reported the bilateral existence of 4 second molars with single roots and single canals in a patient using radiographs, but no endodontic treatment was performed. Ioannidis et al. [10] reported the existence of 7 maxillary and mandibular molars with single roots and single canals using CBCT. But in our case, contralateral second molar had three roots.

Various authors have highlighted the use of dental operating microscope to diagnose aberrations in the root canal anatomy. [16],[17] In this case, presence of a single root and a single canal was clearly identified with dental operating microscope. To ascertain the three-dimensional morphology of this single canal from the cervical region to the apex, dental imaging with the help of CBCT was therefore planned.

CBCT produces geometrically accurate 3-dimensional scans of the maxillofacial skeleton at a considerably lower radiation dose than conventional CT. [18] CBCT technology aids in the diagnosis of endodontic pathosis, assessing root and alveolar fractures, analysis of resorptive lesions, identification of pathosis of non endodontic origin, and pre-surgical assessment before root-end surgery. [19],[20],[21] In our case, the axial planes at the coronal third [Figure 5]a displayed a single, wide but gradually decreasing, oval-shaped canal with a large buccolingual diameter and a small mesiodistal diameter in the middle [Figure 5]b and the apical third [Figure 5]c. The coronal sections and the sagittal sections exhibited a single, conical root canal configuration.{Figure 5}


The present case report describes the endodontic management of a maxillary second molar with a single root and a single canal with the help of dental operating microscope and CBCT. Features of multi-rooted tooth with single root canal:

Radiographically the roots are fused/closer together.Root canal is normally located at the centre and is comparatively larger in size than when multiple canals are found.No evidence of root dentin map.


"I affirm that I/We have no financial affiliation or involvement with any commercial organization with direct financial interest in the subject or materials discussed in this manuscript, nor have any such arrangements existed in the past three years. Any other potential conflict of interest is disclosed."


1Malagnino V, Gallottini L, Passariello P. Some unusual clinical cases on root canal anatomy of permanent maxillary molars. J Endod 1997;23:127-8.
2Kottoor J, Velmurugan N, Surendran S. Endodontic Management of a Maxillary First Molar with Eight Root Canal Systems Evaluated Using Cone-beam Computed Tomography Scanning: A Case Report. J Endod 2011;37:715-9.
3Libfeld H, Rotstein I. Incidence of four-rooted maxillary second molars: Literature review and radiographic survey of 1, 200 teeth. J Endod 1989;15:129-31.
4Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg Oral Med Oral Pathol 1974;37:762-72.
5Barbizam JV, Ribeiro RG, Tanomaru Filho M. Unusual anatomy of permanent maxillary molars. J Endod 2004;30:668-71.
6Deveaux E. Maxillary second molar with two palatal roots. J Endod 1999;25:571-3.
7Fahid A, Taintor JF. Maxillary second molar with three buccal roots. J Endod 1988;14:181-3.
8Kottoor 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:e162-5.
9Fava LR, Weinfeld I, Fabri FP, Pais CR. Four second molars with single roots and single canals in the same patient: A case report. Int Endod J 2000;33:138-42.
10Ioannidis K, Lambrianidis T, Beltes P, Besi E, Malliari M. Endodontic management and cone beam computed tomography evaluation of seven maxillary and Mandibular molars with single roots and single canals in a patient. J Endod 2011;37:103-9.
11La SH, Jung DH, Kim EC, Min KS. Identification of independent middle mesial canal in mandibular first molar using cone-beam computed tomography imaging. J Endod 2010;36:542-5.
12Hartwell G, Bellizzi R. Clinical investigation of in vivo endodontically treated mandibular and maxillary molars. J Endod 1982;8:555-7.
13Peikoff MD, Christie WH, Fogel HM. The maxillary second molar: Variations in the number of roots and canals. Int Endod J 1996;29:365-9.
14Carlsen O, Alexandersen V, Heitmann T, Jakobsen P. Root canals in one-rooted maxillary second molars. Scand J Dent Res 1992;100:249-56.
15Neelakantan P, Subbarao C, Ahuja R, Subbarao CV, Gutmann JL. Cone-Beam Computed Tomography Study of Root and Canal Morphology of Maxillary First and Second Molars in an Indian Population. J Endod 2010;36:1622-7.
16Buhrley LJ, Barrows MJ, BeGole EA, Wenckus CS. Effect of magnification on locating the MB2 canal in maxillary molars. J Endod 2002;28:324-7.
17Matherne RP, Angelopoulos C, Kulild JC, Tira D. Use of cone-beam computed tomography to identify root canal systems in vitro. J Endod 2008;34:87-9.
18Mozzo P, Procacci C, Tacconi A, Martini PT, Andreis IA. A new volumetric CT machine for dental imaging based on the cone-beam technique: Preliminary results. Eur Radiol 1998;8:1558-64.
19Patel S, Dawood A, Ford TP, Whaites E. The potential applications of cone beam computed tomography in the management of endodontic problems. Int Endod J 2007;40:818-30.
20Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG. Endodontic applications of cone-beam volumetric tomography. J Endod 2007;33:1121-32.
21Tyndall DA, Rathore S. Cone-beam CT diagnostic applications: Caries, periodontal bone assessment, and endodontic applications. Dent Clin North Am 2008;52:825-41.