4.7
Accessory Canals and Complexities of the Root Canal System
Frédéric Bukiet, Thomas Giraud, and Benoit Ballester
Objectives
At the end of this case, the reader should appreciate the anatomical variations and the complexities of the root canal system and how it could impact the management and prognosis of treatment.
Introduction
A 28‐year‐old female had continued pain despite treatment with a course of antibiotics from her general dentist. After consulting a dental emergency department, she was finally referred to an endodontist for the management of the symptomatic tooth.
Chief Complaint
The patient complained of spontaneous throbbing symptoms from the lower right second premolar (LR5) that had resolved since she presented to a dental emergency department.
Medical History
Unremarkable.
Dental History
The patient attended her general dental practitioner regularly and had a minimally restored dentition. She presented to her dentist with spontaneous pain and biting sensitivity from the LR5. Antibiotics were prescribed. However, the symptoms became worse one month later and the patient presented to an emergency dental department for pain relief. Root canal treatment was initiated, but technical difficulties were encountered by the practitioner. A temporary dressing was placed and antibiotics were prescribed. The patient was referred to a specialist endodontist.
Clinical Examination
Extraoral examination was unremarkable. Intraoral examination revealed a provisional restoration on the tooth LR5. The oral hygiene was good and the periodontal probing depths were all less than 2 mm. The adjacent teeth were unrestored. The LR5 was tender to percussion; the LR4 and LR6 were both responsive to sensibility tests while the LR5 was not.
What did the periapical radiograph of tooth LR5 reveal (Figure 4.7.1)?
- Distal perforation at the alveolar crest of LR5.
- LR5 restoration extending into pulp chamber with bifurcation of root canal at mid‐root level, two roots with canal only visible in the mesial root.
- LR5 periapical radiolucency surrounding the mesial and distal apices and the bifurcation area.
A cone beam computed tomography (CBCT) scan was taken to fully assess the complexity of the root canal anatomy.
What did the cone beam computed tomography reveal (Figure 4.7.2)?
- A C‐shaped cross‐sectional morphology with multiple root canal irregularities indicating possible fins, cul‐de‐sacs and most likely internal resorption defects (moth‐eaten appearance). The presence of accessory canals was also suspected.
- A large bone destruction including the buccal cortex from the middle third to the periapical area.
- A suspected subgingival perforation on the distal aspect of LR5.
Diagnosis and Treatment Planning
The diagnosis of the LR5 was pulpal necrosis with symptomatic apical periodontitis and internal inflammatory root resorption.
What were the treatment options for the patient?
- No treatment (not suitable considering the history and the diagnosis).
- Non‐surgical root canal treatment.
- Extraction.
After discussion with the patient, it was decided to attempt non‐surgical root canal treatment on tooth LR5 with management of the distal subgingival perforation. The purpose of the treatment was to maintain the tooth but also to regenerate the bone support.
Treatment
Under local anaesthesia and after dental dam placement, the provisional restoration was removed. The distal perforation was temporarily restored to prevent saliva leaking into the root canal and to prevent irrigant leaking out into the soft tissues. Two canals were located and shaped and thoroughly cleaned and disinfected with 3% sodium hypochlorite. Then 17% EDTA was used to remove the smear layer after root canal preparation, followed by a final sodium hypochlorite agitation/rinse. After gutta percha cone adjustment (Figure 4.7.3), the canals were dried with sterile paper points, obturated, and a provisional restoration was placed. The post‐operative radiograph showed satisfactory obturation (Figure 4.7.4). An apical delta, a loop accessory canal and many root canal irregularities previously observed on the pre‐operative CBCT appeared as obturated on the immediate post‐operative radiographs.
Stay updated, free dental videos. Join our Telegram channel
VIDEdental - Online dental courses
