Decay under the restoration
The most common reason. Bacteria creep along the join between filling and tooth, soften the dentine beneath and the restoration loses its foundation. New decay must be removed before anything goes back in.
Wimpole Street opens 1 October 2026. For a dental emergency today, call South Kensington 020 7183 2362 (open 7 days) or St Paul's 020 7183 3709 (Mon–Fri).
South Kensington
Open seven days a week
St Paul's, City of London
Open Monday to Friday
Emergency dentistry · Wimpole Street, Marylebone
Lost filling or crown: protecting the tooth underneath
A filling that crumbles out over dinner or a crown that lifts off with a piece of toffee rarely hurts much at first, which is exactly why people leave it. Underneath, though, is exposed dentine or a prepared stump that was never meant to meet the mouth. Left for a fortnight it collects bacteria, becomes sensitive and can shift so that the original crown no longer fits. This page explains what to do with the piece, what we can re-use, and what it costs. Wimpole Street opens on 1 October 2026; until then, please phone South Kensington or St Paul’s.
Before you are seen
Right now: what to do
- 01
Retrieve the crown or filling if you can and rinse it. Put it in a small bag or pot and bring it with you; an intact crown can frequently be cleaned and re-cemented.
- 02
Rinse your mouth with warm salt water to clear debris from the cavity or stump.
- 03
If the tooth is sensitive, a pharmacy temporary filling material or a piece of sugar-free gum pressed into the space will shield it for a day or two. Do not use household glue of any kind.
- 04
A crown can be temporarily reseated with a little toothpaste or denture adhesive if it clicks back into place easily, but take it out at night so it cannot be swallowed or inhaled while you sleep.
- 05
Chew on the opposite side and avoid very hot, cold or sweet food and drink.
- 06
Take a painkiller as directed on the pack only if you need it, and avoid placing anything medicated against the gum.
Take any painkiller only as directed on the pack, never place aspirin against the gum, and ask a pharmacist if you already take other medicines.
Diagnosis
What's likely causing it
Cement washout
Crowns are held on with cement that slowly dissolves over years. Eventually the seal fails, the crown loosens and one sticky mouthful lifts it off. The crown itself is often perfectly reusable.
Fractured tooth beneath
Sometimes it is the tooth, not the filling, that has broken. A cusp shears off and takes part of the filling with it. The tooth may then need a larger restoration or a crown.
Large, old filling
Amalgam or composite fillings that make up most of the tooth flex under load. After many years of chewing they crack or debond, usually without warning.
Grinding and clenching
Heavy night-time forces fatigue restorations and cement seals faster. Repeated losses of the same crown often point to bruxism rather than poor workmanship.
Short or worn preparation
If the stump under a crown is very short, there is little for cement to grip. Such crowns may need a post, a new preparation or a different design to stay put.
At the clinic
How the emergency visit runs
- Step 1
Inspect the piece
We check whether the crown or fragment is intact, whether its inside is clean and whether it still seats accurately on the tooth.
- Step 2
Examine the tooth
The stump or cavity is examined for decay, cracks and sensitivity, with an X-ray to look at the root and bone beneath.
- Step 3
Numb if needed
Exposed dentine can be sensitive, so local anaesthetic is offered before any cleaning or drilling.
- Step 4
Restore
A sound crown is cleaned and re-cemented. A lost filling is replaced with composite, or a temporary is placed if the tooth needs a crown or onlay.
- Step 5
Plan ahead
If the tooth needs a new crown or the old one cannot be saved, you leave with a written plan, price and appointment for the definitive work.
Fees
Emergency fees
Bringing the crown with you can save several hundred pounds. Around half of lost crowns can be re-cemented; the rest have decay, damage or a fit problem that needs a fresh restoration.
| Item | Fee |
|---|---|
Emergency assessment New-patient rate (usual fee £95). | £30 |
Digital X-ray Per image. | £20 |
Crown re-cementation Where the existing crown is intact and fits. | from £95 |
Temporary filling or crown Protects the tooth while a new restoration is made. | from £95 |
Composite filling Replacement of a lost filling, including any decay removal. | from £185 |
Inlay or onlay For larger cavities where a filling would be too weak. | from £695 |
New crown If the old crown is damaged or the tooth has changed. | from £995 |
Root canal treatment Only if decay has reached the nerve. | £695–£895 |
Indicative prices for Wimpole Street, identical to our South Kensington and St Paul's clinics. Whatever is recommended is set out in writing, with the cost, before any treatment starts.
Once you are home
Afterwards
- After re-cementation, avoid chewing on the crown for an hour and skip sticky or very hard foods for the rest of the day while the cement reaches full strength.
- Mild sensitivity to cold for a week or two after a new filling is common and should fade. Pain on biting that does not improve needs checking.
- Floss around the tooth daily, sliding the floss out sideways rather than snapping it upwards past the crown edge.
- If the same crown has come off more than once, ask us about a night guard; grinding is the usual reason.
- Temporary restorations are meant to last weeks, not months. Keep the appointment for the definitive crown or onlay.
- Book a routine examination if you have not had one recently; other ageing fillings are worth checking before they fail in the same way.
FAQ
Questions patients ask
Often, yes, provided it is undamaged, the tooth underneath is free of decay and the crown still seats fully. We clean the inside, check the fit and bond it back with fresh cement. If the tooth has changed shape or decayed, a new crown is needed.
Swallowed crowns pass through the digestive system without harm in almost all cases, though we will need to make a new one. If you coughed or felt it go down the wrong way, seek medical advice, as an inhaled crown needs to be located.
A few days is usually fine if the tooth is comfortable; a week or more risks decay, sensitivity and drifting of the tooth so that the crown no longer fits. Phone sooner if there is pain.
It is urgent rather than an emergency in most cases. The exceptions are sharp pain, a jagged edge cutting the tongue or cheek, or a front tooth affecting your appearance for work. Those merit a prompt appointment.
For a day or two, yes. Kits from a pharmacy are designed to be removed by a dentist. Avoid household adhesives entirely; they are toxic to the pulp and can make the tooth unrestorable.
South Kensington on 020 7183 2362 is open every day of the week and St Paul’s on 020 7183 3709 covers weekdays. Both can re-cement crowns and replace fillings at the fees shown on this page.
Also on this site
Other emergencies we treat
Marylebone, W1
Emergency care at Wimpole Street from 1 October 2026
Register your interest and we will contact you as the Marylebone diary opens. Anything that hurts today should go to South Kensington or St Paul's, where the same clinicians keep emergency slots each day.
Opening 1 October 2026
Wimpole Street is not yet seeing patients. Until then, please book or call our South Kensington clinic on 020 7183 2362 or our St Paul's clinic on 020 7183 3709. Questions about the new clinic: wimpolestreet@md.co.uk.
Until we open
Need an appointment before 1 October 2026?
The same clinical team already works from two other Medical & Dental clinics. Book at either one now and, if you prefer, move your ongoing care to Wimpole Street once the doors open.
South Kensington
- 20 Old Brompton Road, London SW7 3DL
- Open seven days a week
- 020 7183 2362
St Paul's, City of London
- 5 Ave Maria Lane, London EC4M 7AQ
- Open Monday to Friday
- 020 7183 3709
