If its a single tooth, possible causes could be a decay or gum related issue. There is no complete remedy with just medication, get an x-ray done of that particular tooth, so that your dentist can give you a definitive treatment plan for good overall longterm prognosis.

For the sensitivity in relation to 1 tooth , local remedies won't work... Do consult a dentist , it has to be a caries , or localized gingival problem can b due to many reasons.. Caries can b filled , gingival disease ll depend on the cause .. So,  After the checkup only dentist can advice u what treatment u need to go for... Don't delay to visit ur dentist...