What to Do If a Crown Falls Off

A crown coming off is alarming out of proportion to its seriousness. In most cases it is not an emergency and is straightforwardly resolved. But the first few hours do matter, and there are two specific mistakes that turn a simple re-cementation into something more involved.

The Immediate Steps

1. Retrieve the crown and keep it. Rinse it gently, and store it somewhere safe — a small container rather than a tissue, which is how crowns end up in bins. Re-cementing your existing crown is faster and less expensive than making a new one.
2. Check whether anything is attached. If part of the tooth or a metal post has come away inside the crown, that changes the situation and is worth mentioning when you call.
3. Clean the exposed tooth gently. Brush carefully. The underlying tooth may be sensitive, and it is often shaped to a taper that feels unfamiliar to the tongue.
4. Call the practice. Describe whether there is pain, whether the crown is intact, and whether anything came out with it. That determines urgency.

What Not to Do

Do not use household glue. Superglue and similar adhesives are not intended for oral use, can damage the tooth and the crown, and frequently make correct re-cementation impossible — occasionally turning a re-cement into a new crown, or worse. This is the single most consequential mistake.

Do not force the crown back on. If it does not seat easily, something is in the way, and forcing it can fracture the underlying tooth.

Do not leave it indefinitely. An uncrowned prepared tooth can be sensitive, is more vulnerable to decay, and neighbouring teeth can drift within weeks. If drift occurs, the original crown may no longer fit.

Do not chew on that side until it has been dealt with. Prepared teeth are structurally weaker than intact ones.

Temporary Dental Cement

Pharmacies sell temporary dental cement, and used sensibly it is a reasonable stopgap — particularly if you are travelling or facing a weekend before an appointment.

Used properly: clean and dry both the crown and the tooth, apply a small amount inside the crown, seat it, bite gently, and remove any excess. Then keep the appointment. Temporary cement is designed to hold for days, not months, and a crown seated at a slightly wrong angle can cause bite problems and decay beneath it.

If the crown does not seat easily and fully, stop. Something has changed and it needs assessment.

When to Be Seen Urgently

• Significant pain, particularly spontaneous or throbbing pain
• Swelling of the gum or face
• Bleeding that does not stop
• A sharp edge cutting your tongue or cheek
• Part of the tooth visibly broken away

Otherwise, a routine appointment within a few days is normally appropriate.

Why It Came Off, and Whether It Can Just Go Back

The reason determines the fix, and it is not always as simple as re-cementing.

• Cement failure over time. The most favourable scenario. If the tooth and crown are sound, re-cementation is usually straightforward.
• Decay under the crown. Common, and it means the decay must be removed first. If enough tooth structure remains, a new crown is made; if not, further treatment may be needed.
• Fracture of the underlying tooth. Changes the plan considerably and may lead to a discussion about the tooth's long-term prospects.
• Insufficient tooth structure for retention. Sometimes a crown repeatedly comes off because there is too little tooth left to hold it. Repeated re-cementation does not resolve this, and a different approach is needed.

If a crown has come off more than once, that pattern is the useful piece of information. It usually means the underlying issue was never the cement.