I have a pain in a tooth on my left hand side. the tooth is broken and the filling that's there is sore. what should i do ?

See a dentist: You should schedule a visit with a dentist as soon as possible to see if the tooth can be restored or if it needs some other treatment in order to save it. The longer you wait, the less chance you have of saving that tooth and the more money you will end up spending for treatment to repair or replace that tooth.

Tooth infection: There are many reasons for your tooth to hurt: exposed dentin, cavity, exposed nerve, infected nerve, crack in the tooth, infected gum, apthous ulcer are a few reasons. The best thing to do is see a dentist to make a visual and an x-ray diagnosis. Waiting will only make it worse.