My 3 year old has a boil on the tooth. what kind of treatment can i give her?

Depends: If the boil is around an erupted tooth, then you must take her to the dentist to rule out an infection. If it is from teething of a tooth erupting, treat it with topical listerine dabbed on with a q-tip, either way best to see your dentist.

Dentist : Your child may have an ulcer or an eruption cyst (swelling over an erupting tooth.) a dentist needs to exam your child because it might be an abscessed tooth, which in a child can be deadly depending upon where it is in the mouth. Children can also experience facial swelling (cellulitis) pretty quickly which complicates treatment. Please see a dentist quickly.