Persistent Pain in a Previously Root-Treated Molar With a Separated File
A 44-year-old woman attends with 4 days of spontaneous, throbbing pain in the mandibular right first molar (46). The tooth had root canal treatment 9 years ago and now has a composite core and a metal–ceramic crown. She reports pain on biting and tenderness to percussion; probing depths are 3–4 mm and there is no swelling. Mouth opening is 34 mm and the tooth is at the end of the arch. A periapical radiograph shows a root filling 1.5 mm short of the apex, a separated 25-mm file fragment in the mesial root, and a 4-mm periapical radiolucency. The distal crown margin is open. The patient flies abroad in 10 days for a six-month work contract and asks you to “just remove the nerve” before she leaves. She is systemically healthy, takes no medication, and has no known allergies.
1. State the most likely diagnosis and explain how the separated instrument and the radiographic findings change your treatment planning.
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Most likely diagnosis: previously treated tooth 46 with symptomatic apical periodontitis. The open distal crown margin and short root filling are plausible contributors. Pain on biting and percussion tenderness fit an acute exacerbation rather than pulpitis, because the pulp is already absent.
Why the fragment matters: a separated 25-mm file in the mesial root makes non-surgical retreatment technically demanding. Before touching the tooth I would obtain a small-volume CBCT to locate the fragment in three dimensions, assess remaining dentine thickness and curvature, and decide whether it is bypassable or retrievable. A radiograph alone underestimates perforation risk. I would also check the crown margin, core integrity, and whether the tooth has an adequate ferrule and is restorable.
Planning implications: the tooth is not simply “needing the nerve removed.” Options are specialist retreatment, apical surgery, or extraction. The 4-mm lesion and short filling suggest infection, and antibiotics alone will not resolve it. I would assess restorability before committing to retreatment and would not start a procedure I could not complete or hand over safely before she travels.
2. Compare definitive management options for tooth 46 and recommend one, taking account of the 10-day travel deadline.
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Options:
- Specialist non-surgical retreatment: remove the crown/core, attempt fragment bypass or retrieval under magnification, debride and re-obturate. Advantages: retains the tooth and avoids surgery. Disadvantages: time, cost, risk of perforation, dentine fracture, or inability to bypass; unlikely to be completed and reviewed within 10 days.
- Apical surgery: root-end resection and retropreparation. Useful if the fragment cannot be bypassed and the root is accessible, but the 34-mm opening and posterior position make access difficult; outcome depends on root anatomy and the crown margin.
- Extraction and later replacement: definitive, predictable relief before travel; loses the tooth, and replacement with an implant or bridge needs planning and bone assessment.
- Interim care only: occlusal adjustment, analgesia, and local measures; antibiotics only if systemic signs develop. This may settle symptoms but does not treat the apical infection.
Recommendation: I would not attempt a compromise pulpectomy. If the tooth is restorable and the patient accepts specialist referral, arrange urgent endodontic assessment; otherwise extract 46 before she leaves and plan replacement on return. The decision should be driven by restorability and the ability to complete care, not by the travel date.
3. What would you record, and how would you obtain valid consent for the plan you recommend?
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Record: chief complaint and history; pulp/periapical diagnosis; probing depths; mobility; radiograph and CBCT findings; crown margin and restorability; the separated file; options discussed, including no treatment; risks of retreatment (perforation, instrument fracture, flare-up, fracture, need for extraction), surgery, and extraction; prognosis; the travel constraint; and the patient’s decision.
Consent: use a structured discussion in a language she understands, with a professional interpreter if needed. Confirm she understands that the tooth has already had root canal treatment and that “removing the nerve” is not the procedure. Explain that definitive retreatment may not be completed in 10 days, and that extraction is a single-visit alternative with different consequences. Give written information and a cost estimate; allow time for questions. Document her choice and capacity. If she declines the recommended option, record the advice given, the risks of delay, and the agreed follow-up. Follow local Kuwaiti MOH documentation and consent requirements, and keep records accurate and contemporaneous.