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Year : 2021  |  Volume : 32  |  Issue : 4  |  Page : 528-532
Endodontic management of pulp canal obliteration using a new single-tooth template: A case series

1 Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Meenakshi Academy of Higher Education And Research (MAHER), Chennai, Tamil Nadu, India
2 Department of Cariology and Endodontology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark

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Date of Submission16-May-2020
Date of Decision07-Aug-2020
Date of Acceptance22-Nov-2020
Date of Web Publication18-May-2022


Background: Guided Endodontics is suggested as a reliable method for management of teeth with pulp canal obliteration (PCO). The guide used for this usually involves multiple teeth to gain stability but is bulky. It is therefore suboptimal to be used along with rubber dam. Aim: To describe the use of a minimized single-tooth guide template in three patients with radiographic evidence of PCO. Design: The template was designed and fabricated using the cone-beam computed tomography (CBCT) scan and a surface scan image of the involved teeth. In all three patients, the root canals were successfully negotiated within 15 minutes, with the template involving only the tooth in focus or with neighboring half of the teeth. The operator stabilized the template if required. Conclusions: This case series shows clinically that successful outcome can be obtained during guided endodontics with the use of a single-tooth template in previously traumatized anterior teeth with PCO.

Keywords: Cone-beam computed tomography, endodontics, guided endodontics, pulp canal obliteration

How to cite this article:
Velmurugan N, Sundar S, Saumya-Rajesh P, Kasabwala K, Shilpa-Jain D P, Sarathy S, Prabakaran K, Haritha J S, Bjørndal L. Endodontic management of pulp canal obliteration using a new single-tooth template: A case series. Indian J Dent Res 2021;32:528-32

How to cite this URL:
Velmurugan N, Sundar S, Saumya-Rajesh P, Kasabwala K, Shilpa-Jain D P, Sarathy S, Prabakaran K, Haritha J S, Bjørndal L. Endodontic management of pulp canal obliteration using a new single-tooth template: A case series. Indian J Dent Res [serial online] 2021 [cited 2023 Jun 7];32:528-32. Available from:

   Introduction Top

Calcific metamorphosis or pulp canal obliteration (PCO) is defined by the American Association of Endodontics (AAE) as the rapid deposition of hard tissue within the pulp space often in response to trauma.[1] The pulp space appears partially or fully calcified and is most often an incidental finding.[2] The endodontic management of teeth with PCO is complex, as iatrogenic errors like perforation, instrument fracture and excessive dentin removal can occur during attempts to negotiate these canals.[3],[4] Even with use of a dental operating microscope, these procedures can be time consuming and need patient cooperation.

The concept of guided endodontics[5],[6],[7],[8],[9] tested on extracted teeth and printed resin teeth has proven to be precise and predictable, enabling faster negotiation of calcified canals. It has also been clinically proven that the use of guided templates for the negotiation of PCO reduces the treatment time compared to the non-guided approach.[9],[10] Connert et al. reported the use of an access template with smaller size burs and termed the procedure as “micro guided endodontics”.[11] Buchgreitz et al. reported 50 clinical cases of PCO that were successfully managed using guided access principles.[8] The guided endodontic concept has also been proven to be very useful for endodontic surgery,[12] auto transplantation[13] and in the management of teeth with anomalous root canals.[14]

However, the guides used in previous reports are fabricated involving multiple teeth and quite large,[14],[15] making an aseptic work flow less optimal, as the rubber dam application is either postponed/delayed until after drilling is performed and the guide is removed. In this case series, a minimized single-tooth template is described as potentially being a more convenient guide for the endodontic management of PCO in anterior teeth, due to a maintained application of rubber dam throughout the treatment.

This case series aimed to show guided endodontics using a minimized single-tooth guide approach with convenient rubber dam application.

   Case Report Top

Case report 1

A 36-year-old female patient reported with a chief complaint of pain on biting in her upper front tooth region for the past one week.The patient's familial and medical histories were non-contributory.She gave a history of trauma 20 years ago. Teeth 11 and 12 were both slightly but similarly discolored [Figure 1]a. The patient had received a conventional non-guided treatment of PCO six months ago using the microscope and ultrasonics in tooth 11, prior to the launching of guided endodontics at the university [Figure 1]b.
Figure 1: Case report no. 1 (a) Pre-operative clinical picture showing discoloured teeth 11 and 12. (b) Pre-operative radiograph showing partially PCO in tooth 12 and previously root canal treated tooth 11. (c) Sagittal plane of CBCT showing partially PCO of tooth 12 (d). Virtual design of drill path and template on CBCT volume of tooth 12. (e) Minimized guide placed intra-orally. (f) Minimized access cavity preparation through incisal edge under microscope of tooth 12. (g) Working length radiograph. (h) Post-operative radiograph (i) 18-month follow-up radiograph

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The patient now complained of mild pain in relation to tooth 12. A diagnosis of pulp necrosis with symptomatic apical periodontitis was made. The patient was then explained about the possibility of an alternative treatment option using a guided approach. Following her consent for the treatment, non-surgical guided endodontic treatment was planned for tooth 12 as this had now become an option. A limited volume cone beam computed tomographic (CBCT) image (voxel size 75-150 μm, Romexis software Planmeca, Finland) was taken [Figure 1]c, following the as low as reasonably achievable (ALARA) principles.[16],[17] Using CBCT images and a surface scan, a minimized single-tooth access template was fabricated [Figure 1]d. The surface scan was performed by scanning a gypsum dental model of the upper arch by using an optical dental scanner (Shining 3D, Zhejiang, China). Along with the surface scan, the CBCT images were uploaded into the virtual planning software Geomagic Freeform plus (Haptic Technology 3D systems, South Carolina, USA). The point of access opening on the minimized single-tooth template was determined by tracing a virtual image of a drill path (0.8 mm Gates-Glidden drill no. 2) from the apical foramen to the patent portion of the root canal, extending up to the incisal edge of the tooth [Figure 1]d. The designed template was exported as a Standard Tessellation Language (STL) file for 3D printing. A single-tooth transparent resin template was then fabricated using an SLA printer (Form 2 SLA 3D printer, Form labs, MA, USA).

Following the administration of local anesthesia with lignocaine and adrenaline (1:80.000) (Lignox, Indoco Remedies Ltd., Mumbai, India) and rubber dam isolation, the access template was placed and the point of entry for access opening was marked [Figure 1]e. Initial access opening was done without the template using a one-fourth size round diamond point (Mani, Tochigi, Japan) under high speed with an air-rotor to penetrate the enamel [Figure 1]f. Further negotiation was done with the template in place using the Long Neck bur (DentsplyMaillefer, Switzerland) followed by Gates-Glidden drills (Mani, Tochigi, Japan) no. 1 and 2 using an endodontic motor (X smart, Dentsply, USA). The template was held in place using the non-operating hand of the clinician for additional stability. Periodic radiographs were taken to check for any deviations during negotiation. The obliterated canal was negotiated in the middle third region. Glidepath was checked using a size 10 C + file (DentsplyMaillefer, Switzerland). Working length was determined using an apex locator and radiograph [Figure 1]g. The canal was enlarged up to size 45 K file (Mani, Tochigi, Japan) using a standardized approach. 3% sodium hypochlorite, 17% Ethylene diamine tetra acetic acid (EDTA) and saline were used as irrigants. Calcium hydroxide mixed with saline was used as an intracanal medicament for two weeks. The intracanal medicament was then removed and obturation was done using gutta-percha cones and AH plus (Dentsply, Switzerland) sealer by cold lateral compaction technique. Access cavity was restored with Smart Dentin Replacement (SDR) Flow+ Bulk Fill Flowable composite (Dentsply Caulk, USA) [Figure 1]h. The patient was asymptomatic during the follow up period of 18 months [Figure 1]i.

Case reports 2 and 3

Two patients, a 46-year-old male [Figure 2] and a 24-year-old female [Figure 3] reported with pain in relation to tooth 21. The patient's familial and medical histories were non-contributory. While the male patient gave a history of trauma 10 years back, the female patient had a trauma three years ago. Both the teeth were tender on percussion and discolored [Figure 2]a and [Figure 3]a. Sensitivity testing using EPT and cold test were negative and periodontal probing was within the normal limits. Intraoral radiographs and limited volume CBCT scan images revealed PCO [Figure 2]b, [Figure 2]c, [Figure 3]b and [Figure 3]c. A diagnosis of pulpal necrosis with symptomatic apical periodontitis was made for tooth 21 for both the patients.
Figure 2: Case report no. 2. (a) Pre-operative clinical picture showing discoloured tooth 21. (b) Pre-operative radiograph showing partially PCO (c) Sagittal section of CBCT showing partially PCO in tooth 21. (d) Virtual drill path traced in CBCT volume of tooth 21. (e) Minimized guide placed intra-orally over the tooth 21. (f) Minimized access cavity preparation through incisal edge under microscope. (g) Working length radiograph. (h) Post-operative radiograph (i) 12-month follow-up radiograph

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Figure 3: Case report no. 3. (a) Pre-operative clinical picture showing discoloured tooth 21. (b) Pre-operative radiograph showing partially PCO. (c) Sagittal section of CBCT showing partially PCO in tooth 21. (d) Virtual drill path traced in CBCT volume of tooth 21. (e) Minimized guide stabilized intraorally using Putty. (f) Minimized access cavity preparation through incisal edge. (g) Working length radiograph. (h) Post-operative obturation radiograph. (i) 12-month follow-up radiograph

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Guided access was planned in both teeth after obtaining consent from the patients [Figure 2]d and [Figure 3]d. A minimized single-tooth template as described in case report 1 was fabricated [Figure 2]e and [Figure 3]e. In case report 3, the single-tooth template was stabilized using a putty impression material (Elite HD + Putty Soft, Zhermack Dental, Italy) to avoid its untoward movement during access opening [Figure 3]e. The same guided protocol was used as described in case report 1 [Figure 2]f and [Figure 3]f. In case report 2, the root canal was patent in the middle third and C + files were used for scouting the canal. The canal was enlarged up to size 50 K-file (Mani, Tochigi, Japan). During shaping and cleaning, 3% of sodium hypochlorite, 17% of EDTA and saline were used as irrigants. The patient in case report 2 received calcium hydroxide (RC Cal, Prime Dental, Maharashtra, India) as an intracanal medicament for 2 weeks. An identical treatment sequence was performed for case report 3, besides the shaping and cleaning, which was performed up to size 60 K File (Mani, Tochigi, Japan). Obturation was done with gutta-percha and AH plus sealer (Dentsply, Switzerland) using the cold lateral compaction technique [Figure 2]h and [Figure 3]h. The access cavities were restored as described in case report 1. Patients were asymptomatic at a follow-up period of 12 months [Figure 2]i and [Figure 3]i.

   Discussion Top

In all the patients, the root canals were successfully negotiated using a minimized single-tooth template for guided access. In endodontics, the vast majority of perforations occur while attempting to negotiate PCO cases.[3],[4] All the teeth in the current case series had PCO extending from 1/3-2/3 of the root canal. The successful outcome confirms the results of a previous ex-vivo study that reported guided templates to aid in accurate access cavity preparation up to the apical third of the root.[6]

Notably, the first ex-vivo study reporting an acceptable accuracy of guided endodontics in general, examined complete PCO, as they used root dentin for mimicking the complete PCO.[5] It is expected that the present single-tooth template should work in complete PCO cases, since the guided path made in the coronal 2/3 of the root produces the stability for the potential negotiation of the remaining apical third of a complete PCO case, as discussed by others.[5]

The non-guided case tooth 11 (case report 1) was negotiated and managed in a conventional manner using the microscope and ultrasonics. A previous study using printed teeth, found the relative volume of substance loss for the guided endodontics approach to range from 7% to 15.4%.[9] In that same study, for the conventional access technique, the dentin removed ranged from 33.8% to 60%. However, all procedures that reduce dentin loss during endodontic treatment seem warranted and needed, as one of the main reasons for long-term survival of root-filled teeth is the strength and integrity of the remaining tooth substance.[18] In this case series, it was apparent from the radiographs that the dentin removal was minimal with the guided access preparation. Besides the minimum loss of dentin in the guided approach, the other significant advantage is the reduced chair side time. In all the three cases, the canals were negotiated within 15 minutes. The non-guided approach with microscope and ultrasonics needs more chair side time.[9],[10]

Recently, Buchgreitz et al. published a case series wherein 50 cases of PCO in human anterior teeth were successfully managed using the guided access.[8] Canal negotiation was successful even in cases where previous attempts to negotiate PCO had failed. The vast majority of the patients were unable to present the cause for the PCO. In this present case series, they all presented with a history of trauma. In case reports 2 and 3 since there was a marked time difference of the trauma, it can be speculated that a more pronounced yellowish discoloration is associated with a time factor as well as the extent of the PCO. Irrespective of the discoloration and age of the patient, the teeth were successfully negotiated using the minimized single-tooth template. This obviates the need to have larger and bulkier access templates that maybe more suboptimal to be used along with a rubber dam.

A limitation of the single-tooth template is that it needs to be held secure in place while access opening is being performed. On indication, stabilization was obtained with a putty impression in case report 3. In terms of single-tooth template, a recent case report also demonstrated the use of an intra-coronal guide approach, for reducing the inter-occlusal distance in more posterior regions, wherein the guide was stabilized using the retention of the access cavity.[19] On the other hand, with regards to stabilization of templates involving multiple teeth, customized anchorage guides[20] and guide sleeves with clamp pins[21],[22] have been used. A relevant consideration of guided endodontics, in general, is the need of an advanced technological platform (CBCT imaging, 3D printing machine, virtual designing using special software), that eventually increases the cost of the treatment.

Recently, Chong et al. demonstrated the effectiveness of the dynamic navigation system for access opening in extracted teeth with simulated canal calcification.[23] The dynamic navigation system is used mainly for accurate and faster implant placement. Infrared motion sensing cameras are used to track the clinician's movements and this is compared with the virtual images and a real-time visual feedback is given to the operator for adjusting their motion.[24] This system was found to be highly accurate and efficient for negotiating calcified canals.[25],[26] It was found to be precise for performing both micro-endodontic surgery as well as an ultraconservative access cavity preparation.[23],[27]

   Conclusion and Clinical Implications Top

This case series demonstrated the successful use of a minimized single-tooth template for negotiation of PCO in traumatized maxillary anterior teeth. Although the printing cost might be reduced for the production of the single-tooth template, the use of CBCT imaging, 3D printing and the software eventually increases the cost of treatment. In contrast, the chair side time is reduced.

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.


The authors would like to acknowledge the contribution of Center for Technology Assisted Reconstructive Surgery (CTARS, Chennai, India) for their valuable inputs for virtual designing of the minimized single-tooth template.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

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Correspondence Address:
Dr. Natanasabapathy Velmurugan
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Chennai - 600 095, Tamil Nadu
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ijdr.IJDR_485_20

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