Whenever something appears to go wrong with your teeth, you want to find out what it is and get it fixed as soon as you can. Some problems are more urgent than others, and getting to a dentist as quickly as possible to fix those problems is the best course of action. Yet, it's not always clear what counts as a dental emergency when you're dealing with, say, something unexpected (like decay on a back tooth that you didn't realise had decay). To determine if you need to find an emergency dentist, look for specific clues.
Any Sign of Infection, Including Pain
Any sign of infection, including pain, is worth calling the dentist about. If you have an active infection (swelling gums, pus, and so on), you don't want to put off seeing the dentist for even a weekend. The infection can get worse and be much harder to treat. Plus, with an infection in your head, it doesn't take long for the infection to spread to other parts of your head, including into your ears. Even if you don't see a problem, if you can feel pain, call the dental office and let them make the call about whether you should set up an emergency appointment or wait until a weekday.
By the way, your regular dentist's office should have an answering service or emergency information even if they themselves don't offer emergency services. If you have a regular dentist, that office should be your first call. You can find an emergency dentist after that if your regular dentist's office can't help.
Bleeding That Won't Stop
It's normal after some dental procedures, such as tooth extraction, to have a little oozing of saliva and a little bloody residue mixed together in the hours after the procedure. This is not full bleeding, and it should stop within a day or so. But if you notice an extraction site or another part of your mouth is actually bleeding, call. Something didn't clot properly, or something was essentially reopened. Your dentist needs to see that to help you avoid infection.
Anything Broken or Knocked Out
You wouldn't wait to call regarding a broken tooth; that's a bonafide emergency. But if you have dental or orthodontic work that suddenly breaks, such as a crown breaking or a permanently cemented retainer popping halfway off your teeth, that's something you should call about immediately, too. Now, the dentist might say that those can wait until the next regular business day, but let them make that decision. Anything that breaks in your mouth can pose an infection risk (such as a broken tooth) or a choking risk (such as a retainer that was supposed to be permanent but that is now half-floating about in your mouth).
If you're not sure if something counts as an emergency, or if you can't tell (such as when a child has a dental problem and can only cry rather than articulate what happened), call an emergency dentist. It is better to be told that something can wait a bit than to assume it can wait. If you assume something will be fine and it's not, you've made things harder on yourself. Call, and at least that way, you'll have notified the dentist that something has gone wrong and can get advice on what to do next. Look into emergency dentistry for more information.