METHODS
The clinician informed the patient of the diagnosis and recommended root
canal treatment. After obtaining consent, local anesthesia was
administered using 1.8 ml of 2% lidocaine with 1:100,000 epinephrine. A
rubber dam was placed to ensure isolation of the operative field. All
subsequent procedures were performed under magnification using loupes.
The existing restoration was removed, the endodontic access cavity was
refined, and a pre-endodontic buildup was completed using composite.
During the clinical examination, four root canals were initially
identified: mesiobuccal (MB), mesiobuccal 2 (MB2), distobuccal (DB), and
palatal (P). Under magnification and with the aid of a DG 16 endodontic
explorer (Hu-Friedy), two small hemorrhagic pinpoints were detected in
the grooves extending from the MB to P and DB to P directions. Further
exploration led to the identification of additional canals, namely MB3
and DB2, which were successfully negotiated using a #8 K-file (MANI,
Dentsply) (Fig. 1b).
The initial access design for the canals was triangular but was modified
to enhance accessibility to the additional canals. An electronic apex
locator (AirPex, Eighteeth, Changzhou Sifary Medical Technology, China)
was used to determine the working lengths of all six canals, and the
measurements were confirmed with a digital radiograph (Fig. 2a). The
first distobuccal canal was found to merge with the second distobuccal
canal in the middle third, continuing as a single canal.
Digital radiovisiographs (Kodak RVG system) taken at a 20-degree angle
revealed the convergence of the MB1 and MB2 canals in the apical third
(Fig. 2b). Initial instrumentation of the canals was performed using
#15 stainless steel K-files (Mani Inc, Tochigi, Japan) with 5% sodium
hypochlorite (Septodont, Saint-Maur-des-Fossés, France) as the irrigant.
The canals were then cleaned and shaped using Protaper rotary
nickel-titanium files (Dentsply Maillefer) with a crown-down technique.
To promote healing, calcium hydroxide (Prime Dental Products, Thane) was
placed as an intracanal medicament, and the access cavity was
temporarily sealed with Cavit-Temp (Ammdent, Mohali, Punjab).
After one week, the tooth was asymptomatic. The final obturation was
completed using Bioceramic sealer (SafeEndo, Vadodara, India) and
Guttapercha (Dentsply Maillefer) (Fig. 3a, 3b). Post-obturation
radiographs were taken to confirm the successful completion of the
procedure (Fig. 4a, 4b). Two weeks after obturation, prosthetic
rehabilitation was carried out with a zirconia crown (Fig. 5a, 5b). At
the six-month follow-up, the patient remained asymptomatic, and
radiographs showed evidence of periapical healing (Fig. 5c).