Missing an extra canal (e.g., MB2)
What it is
Completing RCT without locating, cleaning, shaping, and obturating all canals in the tooth — classically missing MB2 in maxillary molars, but it can be any additional canal (e.g., middle mesial, extra distal, etc.).
Why it happens
• Underestimating canal anatomy variability (assuming "one root = one canal") • Inadequate access cavity (can't see the pulpal floor map clearly; no straight-line access to the MB groove) • No magnification/illumination (loupes/microscope) → MB2 orifices are often small and hidden • No troughing strategy (MB2 commonly lies along the groove between MB1 and palatal canal region) • Calcification, secondary dentin, or previous restorations obscuring landmarks • Over-reliance on a single periapical radiograph (2D overlap can hide canals); CBCT not used when indicated
The full clinical mistake entry includes
- How to avoid it — the prevention protocol
- The clinical tip experienced clinicians use
- The documented reference behind the mistake
More clinical mistakes
Dentalverse is an educational resource for dental students and dentists. This page is a study reference — it is not medical advice and does not replace clinical judgment. Always follow your institution's protocols and your supervisor's guidance.