Whenever I get a toothache I think back to see if I took large amounts of vitamins, especially C, and then suddenly stopped. Toothaches can be the result of sudden withdrawal from vitamin C. If so, it's best to return to using it and gradually withdraw from its use rather than do it all at once. Sudden withdrawal from C can cause joint pains as well. Such pains are normally temporary, but they can be quite disconcerting if one doesn't know their source.
if you have a tooth ache and don't want to go to the dentist, here is a cure: take 1000 mg of vitamin C plus one capsule of Echinacea Root. Make sure it has 450 mg of Echinacea and take it twice a day for about 2 weeks. The pain will go away and then you don't have to take anything. One more thing -- don't take them all at once, take them like 9 am and 9 pm or some like that. if you can't take the pain take some pain pills with it. I have a bad tooth and no pain and i don't take any thing for it.