Some conditions include poorly controlled diabetes, knee
/hip replacement surgery, valvular problems in the heart, etc.
If the infection is extensive and there is a risk for airway obstruction or spread to other places of the face/head, then antibiotics should be given. Usually if the infection is minor, extraction will solve the problem.
An infected area is highly acidic due to the production of acid by bacteria in an abscess. An anesthetic solution is basic.