Case report: Root canal treatment of maxillary second molar with a C - shaped distal buccal root: Is it a fused tooth?

INTRODUCTION AND

IMPORTANCE

Fusion of the maxillary second molar (MSMs) and the maxillary third molar is a rare dental anomaly, posing challenges in diagnosis and treatment due to complex root and canal anatomy, which can lead to caries, periodontal, and pulpal issues. While extraction is sometimes favored, root canal therapy (RCT) can preserve natural dentition and improve patient outcomes.

CASE PRESENTATION: A 40-year-old woman underwent a failed extraction of the left maxillary third molar and had chronic periapical inflammation in a fused maxillary second and third molar caused by severe caries. The clinical examination revealed deep carious lesions with pulp exposure, and radiography confirmed fused roots and periapical radiolucency. Under operating microscopy, RCT was performed: four root canals were identified, shaped with nickel‑titanium files, and obturated using warm vertical compaction with gutta-percha and sealer. Post-treatment radiographs verified proper filling.

CLINICAL DISCUSSION: Advanced imaging and microscope-assisted endodontics were crucial for accurate diagnosis and treatment. However, the patient adhered to dietary advice; however, suboptimal oral hygiene led to mild gingival inflammation at the 4-month follow-up. Long-term monitoring is needed to assess potential complications.

CONCLUSION

The periapical inflammation of the fused tooth was cured after root canal treatment, demonstrating its effectiveness as a conservative alternative to extraction for similar anomalies. Future cases should focus on thorough assessment, patient education, and long-term follow-up.