My dentist has pulled my abscessed tooth. do i need totake antibiotics?

Yes: Yes, unless you already finished them.

Ask your dentist: Every situation / patient is different, so you may need to ask your dentist. Depending on the size of the infection and the condition of the tooth your dentist will determine if antibiotics are needed. In some cases, antibiotics are used prior to the extraction to reduce the infection because sometimes it is more difficult to get numb with an infection.

Not necessarily: Having the tooth pulled removes the source of the infection and usually allows your body to heal the rest.

That depends: That depends on how big the abscess is. Removing the tooth eliminates the source of the infection. If the abscess was confined just to the area under the tooth than no antibiotic is usually needed. If the abscess was deep and/or large then an antibiotic will help the body eliminate the remaining infection more effectively. The dentist who treated you should be able to offer you guidance.