if you've just bust a bit off the tooth/filling then all may not be lost and it'll just need patching up. If it's totally knackered then it'll need to come out and the sooner its done the better.
Emergency dentistry:
1. get everything checked and fixed before you go.
2. get an emergency repair kit from a chemist (a certain place with an oval blue logo do one)
3. if something happens get it seen to as soon as possible
Holes - clean out the cavity as much as possible, pack with temporary filling material (roll up blob of material, place on finger, squidge into hole if you can - if not use a friend to help, bite down a few times and then be careful until it sets.
Crowns - try and glue back in ASAP to stop gunge getting into the hole. Always keep any crown you can't get back in cos the dentist usually can. Don't be temped to try..
Superglue - toxic and far too easy to stick everything together.
Araldite - even nastier than superglue and won't come out.
Evostick - contact adhesive, won't work and poisonous.
They have all been tried and the results are usually a bit of a talking point!
Broken dentures - if the bits fit back together then you can try superglue but if you get it wrong it won't fit. Check the glue has set before putting in mouth (sounds obvious but the results are unpleasant if you glue it in)
Broken teeth:
Small bit - patch up as a hole
Big bit (solid) - go see the dentist
Big bit (loose) - can try to remove very loose bits (This WILL hurt), see dentist ASAP, can get infected very easily.
Toothache (no swelling) - Simple painkillers (paracetamol, ibuprofen etc read and FOLLOW the instructions, don't get inventive), avoid things that make it worse, make an appointment.
Toothache (small swelling near tooth) - Painkillers, cold water near the tooth may help, don't place things like Asprin near to tooth - you'll just get a chemical burn in your cheek, see dentist ASAP. Needs tooth fixing.
Toothache (swelling in cheek/side of face) - See dentist TODAY, can spread and cause problems with breathing if swelling gets worse. May need antibiotics, definately needs tooth fixing/out