Root Canals and Crowns
Why did my crown fall off, and what should I do?
31 August 2026 · The Dentist, Al Qusais, Dubai
The short answer
Crowns most often come loose because the cement holding them has slowly broken down, or because decay has formed on the tooth underneath, weakening the seal. Sometimes a knock, sticky food, or grinding at night is the trigger. Keep the crown if you can find it, avoid chewing on that side, and get it looked at within a few days, since leaving the tooth uncovered lets bacteria in and can let the tooth shift out of position.
What actually causes a crown to come off
Every crown is held on with a thin layer of dental cement between the crown and your natural tooth (or the post underneath it, if you've had a root canal). That cement does two jobs: it locks the crown in place and it seals the join so bacteria can't sneak underneath. Over years, cement can slowly break down from the constant flexing of chewing, from acidic drinks, or simply from age. Once it thins out enough, the crown loses its grip.
The other common cause is decay forming at the edge of the crown, right where it meets your gum or the tooth surface. If bacteria get a foothold there, they eat away at the tooth structure the crown was cemented to. Eventually there's not enough sound tooth left for the crown to hold onto, and it comes off even though the cement itself was fine. This is more likely if the crown is old, if you've had gum recession exposing the margin, or if oral hygiene around that tooth has slipped.
Less often, it's mechanical: biting down on something hard like ice or a toffee, a blow to the face, or grinding your teeth at night puts sideways force on the crown that the cement wasn't designed to handle. If a crown keeps coming off repeatedly, that's usually a sign of one of these underlying issues rather than bad luck, and it's worth having the tooth properly assessed rather than just re-cementing it each time.
What to do in the first 24 to 48 hours
Find the crown and keep it somewhere safe, ideally in a small container rather than loose in a pocket or bag. Don't try to glue it back on yourself with household adhesive. It won't seal properly, it can be toxic if swallowed, and it makes the dentist's job harder when they do see you, because they have to clean off whatever you used.
The exposed tooth underneath is often sensitive to hot, cold, and air, since the crown was protecting the nerve or the dentine layer. Stick to lukewarm food, chew on the other side of your mouth, and avoid very sweet or sticky foods that can irritate the area or get stuck against the exposed tooth. If there's any sharp edge, a small bit of orthodontic wax or even sugar-free chewing gum pressed gently over it can protect your tongue and cheek until you're seen.
If the tooth had a root canal, it usually won't hurt much because the nerve is gone. If it still has a live nerve, sensitivity or even a dull ache is normal for a day or two. Pain that is sharp, throbbing, or gets worse rather than settling is worth mentioning specifically when you book, since it can mean the nerve is more irritated than usual.
Why you shouldn't leave it uncovered for long
An exposed tooth isn't just uncomfortable, it's vulnerable. Without the crown's coverage, the tooth can pick up new decay quickly, especially if there's already some cement breakdown or a small gap at the margin. Neighbouring teeth can also start to drift into the space over a matter of weeks, which then makes it harder to seat the original crown back in properly and may mean a new one is needed instead.
When you come in, the dentist checks whether the crown itself is intact and whether the tooth underneath is healthy enough to re-cement it, or whether there's decay or a crack that needs treating first. Often the same crown can go straight back on with fresh cement in a single short visit. If the tooth has changed shape from decay, or the crown has a hairline fracture, a replacement crown is the more honest fix, and you'd get a written quote before anything is done.
If your crown has come off, the practical next step is to book an appointment with us at The Dentist in Al Qusais through WhatsApp or thedentist.ae/book. We're open Monday to Friday 11:00 to 21:00 and Saturday 13:00 to 21:00, and if it's your first visit with us, the checkup itself is free, so there's no cost barrier to getting it checked properly before it turns into a bigger problem.
This article is general information, not a diagnosis. If you are in Dubai, the free first checkup at our Al Qusais clinic is the fastest way to get an answer about your own teeth.