Saudi Endodontic Journal

: 2018  |  Volume : 8  |  Issue : 3  |  Page : 217--221

The use of cone-beam computed tomography in localizing calcified canals during endodontic treatment

Amal Abdullah Almohaimede 
 Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh 11432, Kingdom of Saudi Arabia

Correspondence Address:
Dr. Amal Abdullah Almohaimede
Dental College, P.O.Box 5967, Riyadh 11432
Kingdom of Saudi Arabia


Canal calcification and obliteration is considered a challenge during root canal treatment. The present case report demonstrates a successful management of calcified pulp chamber and coronal third of the root canals of lower right first molar tooth of a 17-year-old patient that was diagnosed as previously initiated with symptomatic apical periodontitis treated by pulpotomy for a long period. It also emphasizes the use of the aiding tools to negotiate such calcification including intraoperative cone-beam computed tomography. This technology, along with chelating agents, magnification, illumination, and ultrasonic instruments helped in assessing the extent and the depth of the calcification and guided the clinician to the correct location, angle, and depth to negotiate the patent part of the canals, and therefore adequately treated.

How to cite this article:
Almohaimede AA. The use of cone-beam computed tomography in localizing calcified canals during endodontic treatment.Saudi Endod J 2018;8:217-221

How to cite this URL:
Almohaimede AA. The use of cone-beam computed tomography in localizing calcified canals during endodontic treatment. Saudi Endod J [serial online] 2018 [cited 2021 Sep 25 ];8:217-221
Available from:

Full Text


Calcific metamorphosis is a common phenomenon that occurs in young patients' teeth following calcium hydroxide (Ca(OH)2) pulpotomy therapy.[1],[2] The increased number of calcium ions leads to the reduction in capillary permeability, which will fail to operate the pyrophosphatase enzyme leading to uncontrolled mineralization.[3],[4] Therefore, the management of teeth with obliterated pulp chamber and calcified canals, which require root canal treatment, is a challenging therapy.[5]

The most commonly used technique to access a calcified canal is to carefully drill through the calcification following the long access of the tooth. Periapical radiograph at multiple angles should be taken to check the direction of the bur to avoid perforation.[6] Ultrasonic and dental operating microscope (DOM) are good tools that help in treating calcified canals.[7],[8] The American Association of Endodontics and the American Academy of Oral and Maxillofacial Radiology were recently updated the joint position statement regarding the use of cone-beam computed tomography (CBCT) in endodontic treatment. They recommended the use of limited field of view (FOV) CBCT in identification and localization of calcified canals.[9]

The purpose of this article was to report a successful management of calcified pulp chamber and coronal third of root canals of a molar tooth by nonsurgical root canal treatment and supported by CBCT scanning as a diagnostic imaging technique.

 Case Report

A 17-year-old Saudi female that was referred to the endodontic clinic complaining of mild-to-moderate pain related to lower right posterior teeth during biting. The patient reported that she started pulpal therapy (pulpotomy) in her lower first right molar (#46) when she was 8 years old. She is medically fit, and according to the American Society of Anesthesiologists (ASA) classification, she is class ASA I.[10]

Clinical examination of tooth #46 showed a glass ionomer restoration. Percussion test revealed mild-to-moderate tenderness and no pain with palpation test. Sensibility test indicated no response, with no signs of swelling, sinus tract, mobility, or deep pockets.

Preoperative periapical radiographic examination revealed periapical radiolucency, narrow mesial canals, and a restorative material encroaching the pulp chamber that was partially calcified [Figure 1]. The tooth was diagnosed as previously initiated with symptomatic apical periodontitis, and the recommended endodontic treatment was nonsurgical.{Figure 1}

The tooth was isolated with a rubber dam, and after proper deroofing of the pulp chamber, the distal canal was accessed; however, both mesial canals were not accessed due to complete orifice calcification. The floor of the pulp chamber was shiny and hard to drill through. Under the microscope (ZEISS microscopy, Jena, Germany), two distal canals, distobuccal (DB) and distolingual (DL), were negotiated. However, the mesial canals could not be negotiated. In the second visit, a decision was taken to view the area with CBCT to locate the mesial canals [Figure 2]a. The mesiolingual (ML) canal was completely calcified compared to the mesiobuccal (MB) [Figure 2]b,[Figure 2]c,[Figure 2]d,[Figure 2]e. Measurements were taken from the floor of the pulp chamber to the first point where the ML and MB canals start to appear in the sagittal view [Figure 2]f,[Figure 2]g,[Figure 2]h. Then, the canals were checked in the axial view [Figure 2]g and [Figure 2]i for areas of calcification and their locations within the canals. Depending on the measured areas along the canal for areas of patency and areas of calcification, drilling within the canals was started using ultrasonic tips (P5 Newtron XS, SATELEC, ACTEON, US) where the MB canal was negotiated [Figure 3]a, then finally, the ML canal was accessed [Figure 3]b. Ethylenediaminetetraacetic acid solution (17% EDTA) (SmearClear ™, Kerr Dental, Orange, California, USA) was used to remove the inorganic debris. Working length was determined using apex locator (Root ZX II J. Morita, Tokoyo, Japan), and confirmed with periapical radiograph. It showed that the two distal canals (DB and DL) were joined at the apical third, and the mesial canals, ML and MB, were separated [Figure 4]a.{Figure 2}{Figure 3}{Figure 4}

All canals were cleaned and shaped using K3 Rotary files (SybronEndo, Orange, California, USA). The DB canal was shaped with K3 0.06 up to size 40, the DL, MB, and ML canals with K3 0.04 up to size 40. Sodium hypochlorite (5.25%) (20 mL) was used as an irrigant. The master gutta-percha cones were checked, and obturation was completed with continuous wave condensation technique and AH-Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland) [Figure 4]b. The access cavity was sealed with a temporary filling material (GC Fuji II LC, Vivadent-Ivoclar) and the patient was referred for the final restoration.


The current case had a pulpotomy treatment with Ca(OH)2 that was left in the pulp chamber for a long period. It is characterized by its ability to induce reparative bridge formation when applied to vital pulpal tissues.[11] However, the pulp chamber and the pulp canal entrances can be subjected to dystrophic calcification after being exposed to Ca(OH)2 for a long period.[1] It was suggested that the high alkaline pH level of Ca(OH)2 irritates the pulp cells and activates the release of bioactive molecules, which stimulate pulpal repair and therefore induce mineralization.[12] Moreover, pulp necrosis may occur due to the reduction of blood supply by this calcification.[13]

The presence of such calcifications is considered a challenge during root canal treatment. Several materials and instruments were used to facilitate overcoming such challenge. Chelating agents in the form of liquid or paste were reported to provide a good help in preparing calcified and narrow root canals.[14],[15],[16],[17] In this case report, a liquid EDTA (17%) solution was used. It has the ability to demineralize and decalcify dental hard tissues.[18],[19],[20] It was recommended to apply the EDTA solution into the pulp chamber to identify the entrance to calcified canals.[15] Goldberg and Spielberg mentioned that the optimal cleaning effect for a chelator is only achieved after 15 min.[21] In contrast, McComb and Smith showed that a chelator had a better effect when it was left for 14 h in the root canal.[22] Furthermore, Weine mentioned in his study that chelating agents may remain active within the canal for 5 days if not inactivated.[23] In this case, EDTA solution was placed in the calcified pulp chamber in between appointments.

Moreover, the use of sodium hypochlorite (NaOCl) may help in identification a calcified canal through the “bubble test” by placing full concentration of NaOCl into the pulp chamber over a calcified canal that contains remnants of pulp tissue, which will result in bubbles formation from the oxygenated tissue.[24] This technique did not help in the current case. The use of the DOM in treating obliterated canals was reported to improve the treatment outcome. This was shown in several studies.[7],[8],[24],[25],[26] Furthermore, variously designed burs and ultrasonic tips have been used to facilitate entering the calcified pulp chambers and canals by performing a deep troughing.[5] In the present case, the DOM and ultrasonic were effective in negotiating the calcification.

Conventional radiography is usually used as the primary imaging modality for assessment of the teeth. However, they represent only a two-dimensional (2D) image of a three-dimensional (3D) object.[27] In addition, the absence of cross-sectional information in the 2D images prevents accurate interpretation of such images.[28]

CBCT was used in the present case. It provides thinly sliced sections in axial, sagittal, and coronal planes of the examined subject.[29] This advantage reduces the anatomic superimposition produced by conventional radiography,[29],[30],[31] and provides the clinicians with an undistorted 3D representation of the anatomic structures.[27],[28],[32]

In this study, the advantage of CBCT in demonstrating anatomic images helped in successful negotiating of the calcified canals without adverse mishaps such as perforations. The preoperative periapical radiograph showed narrow mesial canals; however, the CBCT showed calcified ML canal (at coronal and middle third) and partial calcification in the MB canal. A study was conducted to detect the correspondence of the radiographic diameter size of a canal with its true diameter, by comparing the canal size on the periapical radiographs with the actual canal diameter histologically. It was concluded that there was a correlation between the radiographic and the histological canal size.[33] However, it was mentioned that the two measurements varied clinically, where the canals could be clear radiographically, but difficult to be located clinically due to the smaller actual size. Contrarily, canals that appear completely calcified radiographically could be easily negotiated clinically. This was explained by the difference in the degree of mineralization between the primary and the secondary dentin, where the secondary dentin is considered less radiodense, which will give the radiographic appearance of a canal with a smaller diameter.[34],[35] In this case, CBCT helped in assessing the extent and the depth of the calcification and provided a guide to the corrected location, angle, and depth to negotiate the patent part of the canals, and therefore properly treated.

The use of CBCT should follow the as low as reasonably achievable (ALARA) principles, in which patients should be exposed to radiation as low as reasonable achievable.[36] However, a modification of the ALARA principle was introduced as ALADA, which stands for “As Low As Diagnostically Acceptable.” That means to have an image that is diagnostically acceptable and interpretable by emphasizing on the real indications and referrals of CBCT, also by choosing the appropriate settings of FOV, milliamperage-seconds, and kilovoltage peak, and by applying high-resolution parameters.[37]


Several aiding tools should be used to negotiate calcified pulp chambers and canals to improve the treatment outcome. The use of CBCT cannot substitute the use of the conventional radiography. However, the advantages and the indications to use this technology should be considered.

Declaration of patient consent

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

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


1Akhlaghi N, Khademi A. Outcomes of vital pulp therapy in permanent teeth with different medicaments based on review of the literature. Dent Res J (Isfahan) 2015;12:406-17.
2Langeland K, Dowden WE, Tronstad L, Langeland LK. Human pulp changes of iatrogenic origin. Oral Surg Oral Med Oral Pathol 1971;32:943-80.
3Heithersay GS. Calcium hydroxide in the treatment of pulpless teeth with associated pathology. J Br Endod Soc 1975;8:74-93.
4Ngeow WC, Thong YL. Gaining access through a calcified pulp chamber: A clinical challenge. Int Endod J 1998;31:367-71.
5McCabe PS, Dummer PM. Pulp canal obliteration: An endodontic diagnosis and treatment challenge. Int Endod J 2012;45:177-97.
6O'Connor RP, De Mayo TJ, Roahen JO. The lateral radiograph: An aid to labiolingual position during treatment of calcified anterior teeth. J Endod 1994;20:183-4.
7Selden HS. The role of a dental operating microscope in improved nonsurgical treatment of “calcified” canals. Oral Surg Oral Med Oral Pathol 1989;68:93-8.
8Reis LC, Nasciemento VD, Lenzi AR. Operative microscopy-indispensable resource for the treatment of pulp canal obliteration-a case report. Braz J Dent Trauma 2009;14:23-6.
9Fayad MI, Nair M, Levin MD, Benavides E, Rubinstein RA, Barghan S, et al. AAE and AAOMR joint position statement: Use of cone beam computed tomography in endodontics 2015 update. Oral Surg Oral Med Oral Pathol Oral Radiol 2015;120:508-12.
10American Society of Anesthesiologists. New classification of physical status. Anesthesiology 1963;24:111.
11Sawicki L, Pameijer CH, Emerich K, Adamowicz-Klepalska B. Histological evaluation of mineral trioxide aggregate and calcium hydroxide in direct pulp capping of human immature permanent teeth. Am J Dent 2008;21:262-6.
12Graham L, Cooper PR, Cassidy N, Nor JE, Sloan AJ, Smith AJ, et al. The effect of calcium hydroxide on solubilisation of bio-active dentine matrix components. Biomaterials 2006;27:2865-73.
13Fuks AB. Pulp therapy for the primary and young permanent dentitions. Dent Clin North Am 2000;44:571-96, vii.
14Nygaard-Østby B. Chelation in root canal therapy: Ethylenediaminetetraacetic acid for cleansing and widening of root canals. Odontol Tidskr 1957;65:3-11.
15Hülsmann M, Heckendorff M, Lennon A. Chelating agents in root canal treatment: Mode of action and indications for their use. Int Endod J 2003;36:810-30.
16Scelza M, Antoniazzi J, Scelza P. Efficacy of final irrigation-a scanning electron microscopic evaluation. J Endod 2000;26:355-8.
17Stewart GG, Kapsimalas P, Rappaport H. EDTA and urea peroxide for root canal preparation. J Am Dent Assoc 1969;78:335-8.
18Hahn FL, Reygadas F. Demineralization of hard tissues. Science 1951;114:462-3.
19Nikiforuk G, Sreebny L. Demineralization of hard tissues by organic chelating agents at neutral pH. J Dent Res 1953;32:859-67.
20Patterson SS.In vivo and in vitro studies of the effect of the disodium slat of ethylenediamine tetra-acetate on human dentine and its endodontic implications. Oral Surg Oral Med Oral Pathol 1963;16:83-103.
21Goldberg F, Spielberg C. The effect of EDTAC and the variation of its working time analyzed with scanning electron microscopy. Oral Surg Oral Med Oral Pathol 1982;53:74-7.
22McComb D, Smith DC. A preliminary scanning electron microscopic study of root canals after endodontic procedures. J Endod 1975;1:238-42.
23Weine FS. Endodontic Therapy. 5th ed. St. Louis: Mosby; 1996.
24Johnson BR. Endodontic access. Gen Dent 2009;57:570-7.
25da Cunha FM, de Souza IM, Monneral J. Pulp canal obliteration subsequent to trauma: perforation management with MTA followed by canal localization and obturation. Braz J Dent Trauma 2009;1:64-8.
26Alrejaie M, Ibrahim NM, Malur MH, AlFouzan K. The use of dental operating microscope by endodontists in the Middle East: A report based on a questionnaire. Saudi Endod J 2018;5:134-7.
27Patel 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.
28Lopes LJ, Gamba TO, Bertinato JV, Freitas DQ. Comparison of panoramic radiography and CBCT to identify maxillary posterior roots invading the maxillary sinus. Dentomaxillofac Radiol 2016;45:20160043.
29Danforth RA. Cone beam volume tomography: A new digital imaging option for dentistry. J Calif Dent Assoc 2003;31:814-5.
30Ok E, Güngör E, Colak M, Altunsoy M, Nur BG, Aǧlarci OS, et al. Evaluation of the relationship between the maxillary posterior teeth and the sinus floor using cone-beam computed tomography. Surg Radiol Anat 2014;36:907-14.
31Goller-Bulut D, Sekerci AE, Köse E, Sisman Y. Cone beam computed tomographic analysis of maxillary premolars and molars to detect the relationship between periapical and marginal bone loss and mucosal thickness of maxillary sinus. Med Oral Patol Oral Cir Bucal 2015;20:e572-9.
32Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG. Endodontic applications of cone-beam volumetric tomography. J Endod 2007;33:1121-32.
33Kuyk JK, Walton RE. Comparison of the radiographic appearance of root canal size to its actual diameter. J Endod 1990;16:528-533.
34MjÖr IA. Microradiography of human coronal dentin. Arch Oral Biol 1966;11:225.
35Scott J, Weber D. Microscopy of the junctional region between human coronal primary and secondary dentine. J Morphol 1977;154:133.
36Beach DA. CBCT use in endodontic diagnosis. Dent Today 2016;35:80, 82-3.
37Jaju PP, Jaju SP. Cone-beam computed tomography: Time to move from ALARA to ALADA. Imgaging Sci Dent 2015;45:263-5.