Do you know what's causing the pain? Is it a chipped tooth, cavity, general pain?
If it's a chipped tooth/cavity, you can try the clove oil as previously mentioned. If there is a section missing, you can try applying OraJel (or most drugs ending with -caine.. yes, including cocaine..) OraJel is benzocaine, and is a local anesthetic. Your saliva will most likely dissolve this rather quickly, but it's helped me in the past. Hell, it may be worth a try anyway. If you're paying, always go for the generic (compare Active Ingredients).
You can also try "dental wax" - the guy at CVS won't know what it is, but if you tell him "its the stuff you put on braces", he should know. Putting dental wax over an exposed tooth can help reduce the pain, particularly in cracked teeth/cavities.
Finally, do everything you can to keep your mouth clean (peroxide, Scope, whatever). There's tons of nasty bacteria in human mouths, and getting an infection on top of everything can make it worse. Sensodyne works great for general dental pain. Also avoid salty/sweet foods - their osmolarity is generally higher than inside your tooth, and can cause that sharp shooting pain.
If you can get some, Neurontin (gabapentin) is pretty good for it too (it's non-narcotic, but it helps deaden the nerves). Friends with seizures may have it prescribed. I believe it uses lactose as a non-active ingrediant, so look out if that's an issue for you. Try taking one pill twice or three times a day (doses vary, talk to a doc before starting any new med), but 1800mg/day isn't a bad dose.
Hope that helps! Good luck!