Non-restorable mandibular molar in a long-term oral bisphosphonate user

Her risk category is low: oral alendronate at osteoporosis dosing carries a MRONJ incidence of roughly 0.01–0.1%, far below the 1–15% reported with monthly intravenous antiresorptives in oncology. Within the low-risk group, however, several modifiers push her toward its upper end: cumulative exposure of 7 years (risk rises after about 4 years), poorly controlled diabetes, and heavy smoking. Stopping the drug 14 months ago does not 'clear' the skeleton, because bisphosphonates bind hydroxyapatite with a terminal half-life measured in years; residual drug remains in bone for a decade or more.

Deferral and a drug holiday are therefore not useful here: there is no evidence that a holiday before oral surgery reduces MRONJ risk, and her physician has already stopped the drug. The tooth is genuinely non-restorable (recurrent caries under the crown, fractured cusp, chronic apical periodontitis with repeated swelling), so retaining it is not a treatment option. My recommendation is to proceed with extraction using an atraumatic technique, with documented informed consent covering the small MRONJ risk and the warning signs of exposed bone. She should be reassured that MRONJ is uncommon in her situation but that follow-up is mandatory.

Pre-operatively: 0.12% chlorhexidine rinse, and effective local anaesthesia so that no force is needed. The core principle is minimal trauma - the risk of MRONJ tracks tissue injury, not the presence of the drug alone. I would use periotomes and luxators to sever the periodontal ligament, deliver the tooth with forceps applied to the root, avoid a large periosteal flap, and if a flap is required keep it full-thickness and minimal. I would smooth sharp bony edges, remove all granulation tissue and any apical pathology, and aim for primary soft-tissue closure with sutures, since an epithelialised mucosa over the site is the outcome that matters.

Post-operatively: chlorhexidine 0.12% twice daily for 2 weeks, simple analgesia (paracetamol with or without an NSAID), soft diet, and strict advice not to smoke during healing. Antibiotics are not routinely required for an atraumatic extraction in an uninfected site; I would prescribe amoxicillin 500 mg three times daily for 5 days only if there is active infection or extensive manipulation. Review at 1 week for suture removal, at 4–8 weeks to confirm mucosal healing, and at 6 months. She should return urgently for any exposed bone persisting beyond 8 weeks, pain, swelling, discharge, or a non-healing socket - these trigger MRONJ staging and, if infected, culture-directed antibiotics and specialist referral.

This moves her from a low-risk to a high-risk patient. Monthly intravenous zoledronic acid combined with denosumab in a malignancy setting is associated with MRONJ rates of roughly 1–15%, with risk rising steeply with duration and with the addition of corticosteroids or anti-angiogenic agents. Denosumab has a short half-life but a rebound effect when stopped, so an abrupt holiday is not a simple solution.

Elective extraction should first be avoided if at all possible. A 7 mm pocket with mobility and apical pathosis is usually a hopeless tooth, but options such as endodontic treatment with periodontal stabilisation, or root submergence/coronal amputation to remove the infected crown while leaving the root within bone, buy time and avoid a mucosal wound. If extraction is unavoidable, I would coordinate with her oncologist: ideally operate at least 4–6 weeks after an infusion and before the next one, and delay until any chemotherapy-induced neutropenia has resolved. The technique is as atraumatic as possible with primary closure, pre- and post-operative chlorhexidine, and systemic antibiotics. She needs close follow-up (2, 4, 8 weeks, then 6-monthly) and clear written warning signs, because prevention and early detection are the only reliable interventions.