Antiresorptive & Osteoporosis Medications

Few questions in implant practice provoke as much reflexive anxiety — and as much avoidable over-caution — as the patient who arrives already taking an antiresorptive drug. The word bisphosphonate on a medication list still triggers, in many clinics, an instinct to defer, to demand a "drug holiday," or to refuse treatment outright. That instinct conflates two clinically distinct populations. The single most important act of judgement in this chapter is to separate them. Osteoporosis-dose antiresorptive therapy is a low-risk situation in which implants are generally appropriate; oncologic, high-dose intravenous antiresorptive therapy is where caution hardens into relative or absolute contraindication. Everything else is detail layered on top of that one split.¹

The hazard these drugs raise is medication-related osteonecrosis of the jaw (MRONJ): exposed, necrotic maxillofacial bone persisting beyond eight weeks in a patient on an antiresorptive or antiangiogenic agent, with no history of head-and-neck radiation. The mechanism is suppressed bone turnover. Bisphosphonates and the RANKL inhibitor denosumab both throttle osteoclastic remodeling — the very process by which the jaw repairs the microtrauma of mastication, extraction, and implant osteotomy. When turnover falls far enough, a focus of bone that would ordinarily be resorbed and replaced instead dies in place. The deeper and more sustained the suppression, the greater the risk; this is why cumulative exposure, expressed through dose, route, and duration, is the organizing axis of the whole topic rather than the drug's name.¹⁵

Two further distinctions run through this chapter and deserve to be named at the outset. The first is between MRONJ and implant failure: they are different endpoints with different evidence. Current data do not show that osteoporosis-dose antiresorptive therapy meaningfully reduces implant survival, yet the same patient still carries a small, non-zero MRONJ risk — so consent must address both, separately.² The second is between two ways an implant can provoke osteonecrosis: implant-surgery-triggered osteonecrosis, arising acutely from the placement procedure itself, and implant-presence-triggered osteonecrosis, arising late around an implant that healed uneventfully years earlier — often against a background of peri-implantitis. The late mechanism means consent and surveillance never truly end.³

Once the dose split is made, risk resolves into three practical tiers. The low-risk tier is the patient on osteoporosis-dose therapy for under four years, with no concurrent corticosteroids and no other turnover-suppressing comorbidity. Here MRONJ risk sits in the ~0.5% range, implants are generally appropriate, and no routine drug holiday is indicated.² The elevated-risk tier is still osteoporosis-dose therapy, but with the risk multipliers that the literature consistently flags: cumulative therapy beyond roughly four years, or concurrent glucocorticoids (frequently for rheumatoid arthritis or other inflammatory disease). A pooled analysis estimates that long-term bisphosphonate use adds about three MRONJ cases per 1,000 patients (adjusted HR ≈ 4.09), a relative increase that is real but absolutely small. This is the zone where a drug holiday becomes a consideration — not a mandate — and where consent and surgical restraint matter most.¹² The high-risk tier is oncologic, high-dose IV (or high-frequency subcutaneous) antiresorptive therapy for skeletal metastases or multiple myeloma, often compounded by antiangiogenic agents and cytotoxic chemotherapy. Here elective implants are generally contraindicated and any necessary surgery belongs in coordination with oncology and oral & maxillofacial surgery.⁴⁵

The phrase "drug holiday" means radically different things across the antiresorptive classes, and the difference is pharmacokinetic. Bisphosphonates bind avidly to hydroxyapatite and embed in the skeleton with a terminal half-life measured in years. Stopping an oral bisphosphonate two months before surgery removes essentially none of the drug already in the jaw; the rationale for a holiday rests on a modest, indirect normalization of surface turnover rather than on clearance, and the supporting evidence is weak. This pharmacology is precisely why the holiday's value is debated.¹ Denosumab behaves oppositely. It is a monoclonal antibody against RANKL with no skeletal binding; its effect is fully reversible and wanes over the second half of each six-month dosing interval. For denosumab the lever is not holiday but timing: schedule elective surgery toward the end of the dosing cycle, in the trough before the next injection, when turnover has partially recovered — and never stop denosumab without a plan, given the rebound vertebral-fracture risk of abrupt cessation.³

The anabolic and dual-acting agents sit apart. Romosozumab, a sclerostin antibody with both bone-forming and modest antiresorptive activity, has only rare MRONJ reports and carries lower jaw risk than bisphosphonates or denosumab. The pure PTH-pathway anabolics — teriparatide and abaloparatide — are not MRONJ risk factors at all; by stimulating bone formation they may even aid healing in selected cases, and teriparatide has been used adjunctively to treat established osteonecrosis. None of this licenses casual prescribing, but it does mean the anabolics should not be lumped with the antiresorptives when stratifying risk.¹

Should osteoporosis-dose antiresorptive therapy be interrupted before implant placement? The honest answer is that the evidence does not support a confident yes. There are no randomized trials; the recommendations rest on expert reasoning and low-quality observational data, and the two major guidance documents do not fully agree (Table 3). What can be said cleanly is this: for the low-risk patient, no holiday is indicated and therapy should not be stopped. For the elevated-risk patient — beyond four years, or on steroids — a holiday may be considered in consultation with the prescriber and only if fracture risk permits, recognizing the weak evidence base. For denosumab, "holiday" is the wrong frame entirely: time the surgery to the dosing trough and keep the patient covered.¹²

This is an area where the guidance itself is evolving, and presenting any single position as settled would misrepresent the field. The two reference documents differ in emphasis. The AAOMS 2022 Position Paper¹ takes a surgically conservative stance: for the higher-exposure osteoporosis patient (> 4 years of oral bisphosphonate, or concurrent steroids), it suggests that clinicians may consider a drug holiday of roughly two months before invasive procedures, provided fracture risk allows — while acknowledging the evidence is weak and there are no controlling trials. The 2025 ONJ Taskforce consensus statement in Endocrine Practice², working from a fresh systematic review, lands a step further toward proceeding: it explicitly suggests that in osteoporosis patients, antiresorptive therapy need not be stopped before implant placement (a weak recommendation on very-low-quality evidence), and finds no consistent association between osteoporosis-dose therapy and implant failure. Both agree on the headline numbers — pooled post-implant MRONJ near 0.5%, a small absolute long-term-bisphosphonate excess — and both reject CTX gating. The practical synthesis is to coordinate with the prescriber and consent to the residual uncertainty rather than to enforce one document's wording as doctrine.

The decision discipline is to fix the indication and dose first — it dominates everything — and only then to layer duration and steroid co-therapy. The selector below reproduces that order. Choose the scenario that matches the patient's medication profile to surface the corresponding pathway, then read it against the prose and tables above. As ever, the output is a teaching scaffold, not a substitute for prescriber consultation.