DISCUSSION
Special attention to root canal anatomy is crucial during root canal
therapy due to its significant variability and complexity. A thorough
understanding of the internal morphology of root canals is essential for
achieving successful endodontic outcomes. Studies have documented a wide
range of variations in the number of roots and root canals in the
maxillary first molar. According to Lee et al., the mesiobuccal root
canal of maxillary first molars presents a particular challenge in
endodontics due to its marked morphological variability.(6)
Research on maxillary first molars has consistently shown that the
second mesiobuccal canal (MB2) is the most frequently encountered, with
incidence rates ranging from 18.6% to 96.1%. The third mesiobuccal
canal (MB3) is less common, with an incidence of 1.3% to 2.4%.(7) The
mesiopalatal canal is reported in 56.8% of cases, followed by the
second distobuccal canal (DB2), found in 1.6% to 9.5% of cases. The
distopalatal canal has the lowest frequency, observed in only 1.7% of
cases.(8) Therefore, meticulous attention is required during endodontic
treatment to prevent complications from untreated or missed canals.
Allan et al. reported that approximately 8.8% of endodontic failures
requiring retreatment were due to untreated missed canals.(9)
Various traditional methods have been used to locate additional canals,
including techniques such as the ”champagne or bubble test” with sodium
hypochlorite, 1% methylene blue staining, sharp explorer canal
exploration, identification of bleeding points, the red line test, the
white line test, and obtaining oblique preoperative radiographs. In this
case, radiographs taken from different angles, combined with a thorough
examination of the pulp chamber floor, effectively revealed the variable
anatomy, making advanced imaging techniques such as spiral computed
tomography (SCT) and cone-beam computed tomography (CBCT) unnecessary.
Although these imaging modalities provide detailed insights into root
and canal anatomy, they also pose a risk of increased radiation exposure
for the patient.
The operator’s experience plays a critical role in successfully locating
and negotiating complex canals in the mesiobuccal root of maxillary
molars. Experienced clinicians demonstrate a higher success rate in
identifying these challenging canals.(10) It is essential for the
operator to allocate adequate time during the procedure to thoroughly
search for additional canals. Clinically, the appearance of off-center
files during exploration or in the working length radiograph may
indicate the presence of extra canals within the root.(11,12) Since the
primary goal for both patients and clinicians is the long-term retention
of natural teeth, endodontic therapy remains the preferred treatment
approach for addressing pulpal and periradicular pathology.