Do not wait for the appointment if

Ring 999 or go to an emergency department

You are finding it hard to breathe, speak or swallow
Your eye is swollen or painful, or your eyesight has changed
There is a lot of swelling inside your mouth, or under your tongue
You cannot open your mouth properly

Do not drive yourself. Ask somebody to take you, or ring an ambulance.

Ring a dentist today — or 111 if you cannot get through

Swelling of the gum, cheek, jaw or neck, however small it starts
A temperature, shivering, or feeling unwell with the tooth
Pain getting rapidly worse, or no longer held by paracetamol
A temporary crown that has come off, or a tooth that has broken further

A GP cannot treat this. An infected tooth can spread into the tissues around it, and that can move within hours — a booked appointment next week is not the answer to a swelling that is growing today. Where to go when it will not wait

What this appointment is for

A crown is a cover that replaces the whole outer surface of a tooth. Not a filling inside it — a new outside for it.

It is the answer when there is not enough sound tooth left to hold a filling, or when a tooth has cracked, worn down, or been root treated and needs protecting from splitting. A filling is supported by the tooth around it. A crown is the other way round: it holds the tooth together.

That is the trade. To put a cover over a tooth, the tooth has to be made smaller first — typically by one to two millimetres all round, which is most of the enamel. It is not reversible, and it is the one thing worth understanding before you agree to it rather than after.

What actually happens

Usually two appointments, with a laboratory making the crown in between.

First appointment — the preparation

The tooth is numbed.
A record of the tooth is taken before anything is done to it, so that a temporary can be made to the right shape.
The tooth is reshaped — reduced all round and on top, and any old filling or decay under it dealt with. If there is very little tooth left, a core is built up first.
An impression or a digital scan is taken of the prepared tooth. Impression material is putty that sets in a couple of minutes and is the part people find unpleasant; a scan is a small camera and no putty. Ask which is used if you gag easily.
The shade is matched, in daylight if possible, against your other teeth.
A temporary crown is cemented on with a deliberately weak cement, because it has to come off cleanly next time.

Between appointments, the laboratory makes the crown. How long that takes varies by practice and by laboratory — commonly a week or two. Ask when it is booked rather than guessing; you will be living with a temporary until then.

Second appointment — fitting

The temporary comes off, the fit and the bite and the colour are checked, and the crown is cemented. Often no injection is needed, though you can ask for one.

Some practices make crowns in-house on the day with a milling machine. If yours does, the two appointments become one longer one.

What it feels like

The injection, then very little. The preparation appointment is longer than a filling and much the same in character: pressure, vibration, water, noise.
The impression is the bit people remember. A couple of minutes of putty and a strong urge to swallow. Breathing through your nose and leaning forwards both genuinely help.
Your gum may be sore afterwards. A thin cord is sometimes tucked into the gum edge to push it back so the margin can be recorded. It is uncomfortable rather than painful and the gum settles in a few days.
The temporary feels different — slightly bulky, a little rough to the tongue, and sometimes sensitive to cold.

How long it takes

The preparation appointment is a long one; the fitting is usually short. The number that actually affects your life is how long the laboratory takes, so ask for that one.

Before you come

Eat beforehand, and allow for being numb afterwards.
Take your medicines as normal, and bring a list.
Say what you take and what you have. Bring the list, and say it out loud rather than assuming it is on file: any blood thinner; bisphosphonates, denosumab or any other bone or osteoporosis medicine; steroids; anything that affects your immune system; diabetes; a heart valve problem or replacement, or endocarditis in the past; pregnancy or breastfeeding; any allergy, including latex and penicillin; and any hospital treatment in the last few months. None of it necessarily changes the appointment. All of it changes whether the decision is made with the full picture.
Say if you gag easily. It changes how the record is taken, and there are real options.
Think about the shade before you arrive. Daylight is better than surgery light, and lipstick genuinely interferes with matching.
Do not plan anything that matters immediately afterwards if it is a front tooth — the temporary will look like a temporary.

Worth asking

What material, and why that one? Metal-backed, all-ceramic and gold all behave differently, look different and wear the opposing tooth differently. There is a reason for the choice and it is worth hearing.
How much tooth is left under it? This is the question that predicts how long the crown lasts, far more than the crown itself does.
Does the tooth need a root canal first, or might it later? A heavily prepared tooth sometimes needs one afterwards, and finding out beforehand that it was a possibility is much better than finding out afterwards that it was.
How long will the laboratory take, and what do I do if the temporary comes off? Ask this one before you leave with a temporary, not at nine o’clock on a Saturday.
What will it cost, including anything underneath it?

Afterwards

Mostly about living with the temporary, and about the bite on the day the real one goes on.

→ After a crown

Your dentist’s instructions come first

The instructions you are given by the dentist who is treating you take precedence over anything on this page. They know your tooth, your history and their plan; this page does not.

Sources

Root canal treatment, including when a crown is needed — NHS, last reviewed 3 October 2025
NHS dental charges and treatment bands — NHS