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.