Case Report:
A 21-year-old female Caucasian patient was referred for the evaluation
of a central incisor due to mobility and a sinus tract. The patient had
previously completed orthodontic therapy, after which a fixed retainer
was placed lingual to the six maxillary anterior teeth. She reported a
history of trauma with a fork, after which she began experiencing
mobility of the tooth and sensitivity while eating. Clinical evaluation
revealed that tooth #21 presented with grade III mobility, pain upon
palpation and percussion, and no response to cold or hot stimuli.
Furthermore, an active sinus tract was present clinically in the area
corresponding with the apex of tooth #21.
Radiographic evaluation with intraoral radiographs revealed the presence
of a periradicular lesion in the mesial part of the root, corresponding
to irregular anatomy in the same area (Figure 2a). In order to further
evaluate the periradicular lesion and the anatomy of the canal system,
cone-beam computed tomography (CBCT) was advised. An evaluation of the
CBCT images revealed a dilaceration of the main root into two individual
root canals in the apical area. The mesial root was found to extend into
the mesial-buccal part of the tooth, as seen from occlusal slices
(Figure 3a-3e). In addition, a complete loss of the buccal wall was
noted, which made the prognosis of endodontic treatment much worse than
initially believed. Since no evidence of previous carious lesions were
found, the pathology might have occurred due to intense orthodontic
movement or a previous trauma which the patient did not recall. The
treatment options were either to treat endodontically, or proceed with
extraction and restore the #21 territory either with a fixed partial
bridge or placing an implant.
The patient was informed about the overall condition of the tooth and
the treatment alternatives. She elected to proceed with the more
conservative treatment option of saving tooth #21 with a root canal
treatment and repositioning of the orthodontic palatal splint, which was
broken.
The tooth was anaesthetised, and isolation was achieved by placing a
rubber dam over the six maxillary anterior teeth and then isolating the
palatal of tooth #21 with a chemical dam. Access was gained with a long
round bur mounted in a high speed handpiece. The pulp chamber was found
to be dark and void of biological content. Through scouting with a 10 k
file, the main canal exit was located, and the working length was
measured with the use of an apex locator (Morita Root ZX, Tokyo, Japan
). Afterwards, the hand file was pre-shaped in the last one millimetre,
and the lateral walls were precisely scouted to locate and enter the
second mesio-buccal canal of the tooth. The working length of the second
canal was also measured with an apex locator. K-files were used to
radiographically confirm the working length (Figure 2b).
Chemomechanical preparation of both canals was performed with 35.04
rotary files (Race Evo, FKG Dentaire, LaChaux de Fonts, Switzerland).
The root canals were copiously irrigated with a 5.25% sodium
hypochlorite solution in a Luer lock syringe with an Iriflex (PD, Le
Lochle, Swicherland) needle. A premixed calcium hydroxide paste was
placed into the canals (Multi-Cal, Pulpdent, Watertown, USA) for a week.
During the second appointment, calcium hydroxide was removed with an Xp
Endo Finisher at 1000 rpm/1 torque (FKG Dentaire, LaChaux de Fonts,
Switzerland) ; then, the same file was used to activate a 5.25% sodium
hypoclorite solution for 30 sec. Afterwards, the canals were irrigated
for 2 min with 17% EDTA, which was also activated for 30 sec. The final
irrigation was performed with sodium hypochlorite for 3 min. Gutta
percha cones were fitted, and the canals were dried with paper cones. A
bioceramic sealer was placed in the canal space (BC sealer, FKG
Dentaire, LaChaux de Fonts, Switzerland), and then the cones were
inserted and cut in the canal orifice using a cold hydraulic technique.
(Figure 2c) A temporary filing was placed (Figure 2d), and the patient
was referred back to her general dentist for the final restoration and
repositioning of the orthodontic splint. Since there were no complaints
and due to the restrictions of the COVID-19 pandemic, the follow-up was
performed after two years. Clinically, the tooth was functional and
stable, and the lesion demonstrated radiographic healing (Figure 2e).
After the finishing the treatment and until the follow-up, the patient
did not experience any pain or discomfort in the area. In the two year
follow-up no discoloration was evidenced in the tooth #21.