Direct answer. Mercury fillings — dental amalgam — are a metal alloy containing roughly half mercury by weight. Mainstream bodies consider them safe for most adults; international policy is nonetheless phasing them out. Removal is sensible when a filling fails or a patient prefers mercury-free care, but drilling out sound fillings without precautions can raise exposure. Assessment first, always.
The honest place to start
Almost everything written about mercury fillings online comes from one of two camps, and both will cost you something. The first camp wants to frighten you: every amalgam is a toxic time bomb, your fatigue is mercury poisoning, book the full-mouth removal today. The second camp wants to wave you away: the science is settled, there is nothing to discuss, stop asking. Neither camp is being straight with you. The first is selling treatment you may not need — and, done carelessly, removal can briefly increase your mercury exposure, which is the detail the fear-marketing never mentions. The second is ignoring the plain fact that world policy is moving away from amalgam, and that a patient's preference for mercury-free dentistry is legitimate without needing a disease to justify it.
This page sits deliberately in the middle, because that is where the evidence sits. Dental & Wellness London has practised integrative dentistry since 2009 — long before "biological dentistry" became a marketing term — and the clinic's position has not changed: tell patients what is known, what is not known, and what is genuinely changing, then let them choose. We say no often here, and "no, those sound fillings don't need to come out this year" is a sentence said more than the fear-marketing camp would like.
What a mercury filling actually is
Dental amalgam is an alloy: roughly 50% elemental mercury bound with silver, tin and copper. The mercury is what makes it workable — it binds the powdered metals into a material that packs into a cavity and sets hard. Dentists have used it for over 150 years because it is strong, tolerant of imperfect conditions, and durable; a well-placed amalgam in a back tooth can serve for decades, and many do.
The honest chemistry: the mercury in a set amalgam is bound within the alloy, but bound is not the same as inert. Set amalgams release very small amounts of mercury vapour continuously, and more during chewing, grinding and — significantly — drilling. The scientific argument has never been about whether vapour is released; it is about whether the amounts involved matter to health.
What the evidence says — and what it doesn't
The mainstream position. The major reviews — from European scientific committees, the FDA, and the UK's dental bodies — conclude that for the general adult population, the mercury exposure from amalgam fillings is well below levels associated with harm, and that no causal link has been established between amalgam and systemic disease. Large studies have looked for connections to neurological and kidney disease in the general population and not found them.
The genuine caveats inside the mainstream position. The same regulators draw boundaries worth knowing. In the UK and EU, amalgam has not been used in children under 15 or in pregnant or breastfeeding women since 2018, except where a dentist deems it strictly necessary. The FDA advises that certain groups — pregnant women, young children, people with kidney impairment or known mercury sensitivity — may reasonably prefer non-mercury alternatives for new fillings. And documented amalgam allergy, typically appearing as lichenoid patches in the mouth next to a filling, is an accepted clinical reason for removal.
What the biological perspective adds. Biological dentistry starts from a precautionary stance: where a material releases a known neurotoxic element at any dose, and well-tested alternatives exist, prefer the alternative — particularly for new restorations. It also points out, fairly, that "no causal link established in population studies" is not the same as "proven harmless for every individual", and that individual susceptibility is genuinely hard to study. What this clinic will not do is convert that precautionary logic into disease claims — the research has not established that amalgams cause chronic fatigue, autoimmune disease or neurological conditions, and a clinic with proper clinical governance will not tell you it has.
What is changing regardless. The Minamata Convention — the global mercury treaty — commits signatories to phasing down amalgam, primarily for environmental reasons: mercury from dental waste ends up in water and ecosystems. The EU has gone further, ending routine amalgam use from 2025; the UK continues a formal phase-down, and NHS use is steadily declining. Amalgam is a material in managed retirement — which is precisely why a calm, unhurried approach to the fillings you already have makes more sense than a panicked one.
The four-question framework used in consultation
When a patient asks "should my mercury fillings come out?", the answer runs through four questions — in order, and the order matters.
1. Is the filling still doing its job?
Amalgams fail like any restoration: cracked margins, decay creeping underneath, fractures in the surrounding tooth. A failing filling needs replacing whatever it is made of, and at that point choosing a mercury-free material is the obvious, uncontroversial decision. A significant share of "amalgam removal" is simply good dentistry happening on schedule.
2. Is there a clinical indication?
Lichenoid reaction adjacent to a filling, confirmed allergy, a tooth that needs crowning anyway, an old amalgam so large the tooth's long-term structure is better served by a designed restoration. These are clinical reasons, assessed tooth by tooth.
3. Is this an informed preference?
A patient who understands the evidence and still prefers mercury-free dentistry — for precautionary reasons, environmental reasons, or simply because they no longer want grey metal in their smile — is making a legitimate choice. The clinic's role is to make sure it is informed, sequenced sensibly, and costed honestly in writing. Sound amalgams do not need to come out this month, and manufactured urgency is a sign of selling, not dentistry.
4. If removal is chosen — how, and in what order?
This is the most practical of the four questions. Drilling an amalgam is the single highest-exposure moment in that filling's life, for patient and clinical team alike. Careful removal technique manages this: isolation of the tooth with a rubber dam, high-volume suction, copious water cooling, sectioning the filling out in pieces rather than grinding it away, and fresh-air protocols. The IAOMT's SMART protocol is the recognised technical standard codifying these precautions. Sequencing matters too — replacing a mouthful of amalgams is staged work across months, not an afternoon's heroics, and each tooth gets its own assessment of what should replace the filling.
What replaces an amalgam — and the whole-health frame
Modern mercury-free options are genuinely good. Composite resin handles most small and medium restorations; ceramic inlays, onlays and crowns handle larger rebuilds where more of the tooth needs replacing. The right replacement is a decision about bite forces, remaining tooth structure and long-term function — designed with the patient's future in mind, not just for the day the amalgam comes out. A poorly chosen white filling that fails in four years has not improved on a sound amalgam that would have lasted fifteen.
Costs depend on the size of the restoration and the material the tooth genuinely needs, so treatment is quoted per written, itemised plan — what each stage costs, what is included, what is not — before anything is booked. A dental examination is £65, and staged plans can be spread with 0% APR finance over 12 months via Tabeo, subject to status.
The whole-health frame matters too, and it is broader than the filling. Dental & Wellness London is an integrative clinic — dentistry alongside Ayurvedic medicine, nutritional therapy and psychological practice under one roof — and the honest whole-health contribution here is not a "mercury detox" (a market best treated with the same scepticism as the fear-marketing). It is this: a patient anxious about their fillings is often a patient anxious about their health generally, and that deserves a calm, structured response — good baseline dentistry, sensible nutrition support where wanted, and an honest map of what their fillings do and do not explain.
Talk it through properly
If you have amalgam fillings and questions — whether they are sound, whether any genuinely need attention, what a staged mercury-free plan would look like and cost — the right next step is an unhurried assessment, in writing, with no urgency attached. A dental examination at Dental & Wellness London is £65.
Call 020 8127 4567 or message on WhatsApp at +44 7974 910222 (8am–7pm). Patients are seen Monday to Friday, 8am–7pm, by appointment at 222 Essex Road, Islington, London N1 3AP.
