Dental abscess. tooth surgically extracted. given amoxycillin 250 mg n metronidazole 200mg q.i.d 4/7. shouldn't 1 course be more than 4 days?

Can't generalize: While antibiotic courses are often longer when used solely to treat infections, in this case a big part of treating your infection was the removal of the offending tooth. Sometimes shorter courses of meds are used to help get the healing started then we rely on your immune system and the healing process. Ask your doctor this question to understand why a short course was prescribed.