Bisphosphonates, Denosumab & Dental Implants: MRONJ Risk Explained

Overview

Bisphosphonates and denosumab are antiresorptive medications that suppress osteoclast activity to treat osteoporosis or skeletal complications of cancer. They are also the central concern in medication-related osteonecrosis of the jaw (MRONJ). This guide summarises the 2022 American Association of Oral and Maxillofacial Surgeons (AAOMS) position paper as it applies to implant patients^[1].

What MRONJ is (and isn't)

MRONJ is defined by three features together:

1. Current or previous treatment with antiresorptive or antiangiogenic agents.
2. Exposed bone or bone that can be probed through a fistula in the maxillofacial region, persistent for > 8 weeks.
3. No history of radiation therapy or metastatic disease to the jaws.

It is not a generic delayed-healing problem; it is bone necrosis that fails to remodel because osteoclastic activity is profoundly suppressed.

Risk tiers by drug, dose, and indication

• Oral bisphosphonates for osteoporosis (alendronate, risedronate): MRONJ incidence after invasive dentoalveolar surgery commonly reported as < 0.5%, rising with duration; the 4-year mark is often used as an inflection point in protocols.
• IV bisphosphonates for osteoporosis (zoledronate 5 mg yearly): low but measurably higher than oral.
• IV bisphosphonates for oncology (zoledronate / pamidronate, frequent dosing): incidence in published series ranges roughly 1–15% depending on cohort and definition — relative contraindication to elective implants.
• Denosumab (Prolia 60 mg q6 mo) for osteoporosis: risk comparable to oral bisphosphonate range.
• Denosumab (Xgeva, oncology dosing): risk comparable to IV oncology bisphosphonates.

Before considering implant surgery

• Confirm drug name, dose, route, and duration in writing.
• Treat active dental disease before starting (or before re-starting) antiresorptive therapy if at all possible.
• For oral bisphosphonate > 4 years: written informed consent specifically mentioning MRONJ; consider physician consult.
• Atraumatic surgery, primary closure, single-tooth sites preferred over full-arch first surgery.
• Consider single-dose perioperative antibiotic per local protocol; chlorhexidine rinse for 4–8 weeks.

Drug holidays: what AAOMS actually says

The 2022 AAOMS position paper notes that evidence supporting routine drug holidays is limited and that decisions must balance MRONJ risk against the systemic risk of stopping antiresorptive therapy (fragility fractures, skeletal events). Any change in dosing belongs to the prescribing physician, not the dentist. CTX (C-terminal telopeptide) testing is sometimes used as a surrogate but is not endorsed as a stand-alone decision tool^[1].

Frequently asked questions

Related reading

• Osteoporosis and implants
• Risks and complications
• Evaluating a provider