If you lose a filling quickly, you should call the dentist to get in as soon as possible.
You can find dental cements at your grocery store or pharmacy that you can use to fill in the gap while you wait.
You can also cover the hole with sugar-free gum, but it’s very important to make sure it’s sugar-free. If sugar gets into the area around the hole, it can cause a lot of pain.

Most swelling is caused by an infection, and if the swelling makes it hard for you to breathe or makes your eye swell up, you need emergency dental care right away and may need antibiotics.
Don’t put heat on an infected area that is swollen because this could make the infection spread faster.

As soon as possible is best.
Getting care quickly is especially important if you knocked out one of your teeth. If you get help within an hour or so, your emergency dentist might be able to put it back in place with a splint.
If you lost a filling, for example, you might be able to take care of yourself for a day or two before going to the dentist.

If you can’t reach your regular dentist because you are out of town or for some other reason, what you should do depends on the details of your situation.
If the problem isn’t too bad, you might decide to wait until you get home to see your regular dentist.
If you have a dental abscess or a tooth gets knocked out, it might be best to call a different dentist and then go back to your regular dentist later.