A crown usually comes off at the worst possible moment: eating something chewy, on a Friday night, or in the middle of a holiday. It is startling, and the tooth underneath feels alarming to the tongue, but on its own a crown coming off is not a painful emergency in most cases. What you do in the first hour, and how long you leave it, makes a real difference to whether the same crown goes back on.
The first ten minutes
Find the crown and keep it. Rinse it under cold water, dry it, and put it somewhere it cannot get crushed or thrown out. A small container or a zip-lock bag, not a tissue on the kitchen bench. If it can be re-fitted, you have just saved yourself the cost of a new one.
Do not put it back in your mouth to “test” it. People do this and then swallow it. If it does get swallowed it almost always passes through without incident, and you should let us know but not panic. If you inhaled it instead — a sudden coughing fit, wheezing, or breathlessness at the moment it disappeared — that is a hospital matter and not a dental one. Go to an emergency department.
Look inside the crown. This tells you more than anything else you can check at home.
- If it is hollow and clean inside, with maybe a film of old cement, the cement seal has simply given way. The tooth underneath is probably intact and there is a good chance we can clean it up and re-fit the same crown.
- If there is a solid lump of tooth or dark filling material wedged inside it, part of the tooth has broken away with the crown. That changes the plan, and it is worth knowing before you arrive so the news is not a surprise.
Look at the tooth. It will not look like a tooth. A prepared tooth is a smooth stump, and it usually looks smaller and darker than people expect. That is normal. What matters is whether it is sharp, whether it is sensitive to air, and whether the gum around it is intact.
What not to do, and why
Do not use superglue, Araldite, or any household adhesive. This is the single most damaging thing people do with a fallen crown, and it comes from good intentions. Three reasons it goes badly. It is not safe to sit in the mouth against gum tissue. It sets almost instantly, so the crown locks in whatever position you happened to push it into, which is rarely the right one, and if the bite is wrong the tooth underneath takes the punishment. And it fills the inside surface of the crown with cured adhesive that cannot be removed cleanly, which is often what turns a crown we could have re-fitted into one we have to remake.
Do not keep taking it in and out. Every insertion scrapes the prepared tooth and irritates the gum.
Do not chew on that side. The prepared tooth has thin walls in places, and biting directly on an unprotected preparation is a genuinely common way to fracture the remaining tooth and lose the option of re-fitting.
Temporary dental cement from the pharmacy is acceptable, for a night or two. If you are away, or it is a front tooth and you have work in the morning, a temporary crown cement kit will hold it. Follow the instructions, seat the crown fully, and bite gently to check it is not high. Treat it as a lift home, not a repair. It is a soft cement that leaks, and decay progresses under a leaking crown quickly.
Looking after the exposed tooth until you are seen
The prepared tooth is dentine, which is porous and has microscopic tubules running to the nerve, so cold air and cold drinks can produce a sharp zing. It usually settles once the crown is back.
- Keep brushing it, gently, with a soft brush. It needs to be clean for us to re-fit anything to it.
- Avoid very cold, very hot, and very sweet things on that side.
- Sensitive toothpaste rubbed onto the stump with a fingertip and left there helps a lot of people.
- Sugar-free gum or dental wax over a sharp edge will stop it shredding your tongue in the meantime.
- If there is throbbing pain, swelling, or a bad taste, that is not just a lost crown. Something underneath needs attention and you should be seen the same day.
Why waiting is the expensive part
This is the part almost nobody explains, and it is the reason we would rather see you this week than next month.
The moment that crown comes off, the prepared tooth stops holding its position. Teeth are not set in concrete: the tooth above or below it begins to over-erupt into the space, and the teeth either side start to drift and tip towards the gap. It happens slowly and painlessly, and it does not take long for a couple of tenths of a millimetre of movement to accumulate. That is enough. The crown was made to fit a space that no longer exists, so it will not seat fully, and a crown that does not seat fully cannot be cemented.
At that point the same crown you carefully kept in a container becomes a remake, at the cost of a new crown, because of movement you could not see or feel.
The prepared tooth is also unsealed. Its margins are exposed and often below the gum line, so plaque collects where you cannot easily reach, and the exposed dentine decays far faster than enamel would. We see teeth that have been left uncovered for a few months where there is no longer enough sound structure to hold a crown at all, which turns a re-cementation into a root canal, a post and core, or an extraction.
If you had a crown come off, keep it, and get it looked at within a few days. That is the whole message.
What happens when you come in
We keep same-day emergency appointments open, and you can text us on 0435 025 318 as well as ring.
The appointment itself is usually short and there is often no need for anaesthetic. We check the crown’s fit surface, clean the tooth, and work out why it came off, because a crown that comes off for no reason is rare. Cement washout, decay at the margin, a fractured core underneath, a bite that has been overloading it, or a root fracture: those are the realistic candidates and they lead to different treatments. We take an X-ray if there is any doubt about what is going on under there.
If the tooth is sound and the crown is intact, we re-fit it, and this is where the re-cementation either lasts or does not. Both surfaces get air-abraded first, a fine stream of aluminium oxide particles that removes the old cement and the film on the tooth. Bonding to residual old cement is bonding to nothing much, and it is the reason re-cemented crowns sometimes fall off again within months. Then we isolate the tooth properly, keep it dry through the whole cementation, remove every trace of excess cement from the margins and between the teeth, and check the bite in side-to-side movements, not just straight up and down. If the bite was what unseated it in the first place, cementing it back without adjusting the bite is a short-term arrangement.
If the tooth has broken, or there is decay under the margin, we will show you the photograph on the screen and set out the options in writing before doing anything beyond making you comfortable.
Practical details
Whitehorse Dental is at 129A Canterbury Road, Blackburn VIC 3130, with on-site parking and a short walk from Blackburn station. We open at 8:00 on Wednesdays and Fridays, run to 6:00 on Mondays, Tuesdays and Thursdays, and open Saturday mornings from 9:00 to 1:00, which is often when crowns actually come off. Call (03) 8838 8820, text 0435 025 318, or book online. Consultations are available in Mandarin, Cantonese, Teochew and Shanghainese as well as English.
Related reading: what a loose crown is telling you · how long crowns last and what decides it · what happens at each crown appointment · our crowns and bridges and emergency dentist pages.