How long do swelling and pain last on an infected tooth day 4 of antibiotics?

Depends on infection: Depending on what is causing the infection and the severity of the tissue lost, it may never quell to the point you feel as if it is all repaired. Teeth do not handle the same way an infection in a soft tissue site does.

Root canal: Just taking antibiotics and waiting for a miracle is not the way to treat an infected tooth.. It might be a a periodontal infection or an accessed tooth that requires treatment. Who gave you antibiotics? A dentist? Or did you have some laying around in your medicine cabinet? I can assure you the problem is not going to go away without the proper treatment. You need to see your dentist asap.

Dental pain: Better consult your dentist . With proper antibiotic and taking proper dose , the pain and swelling should be reducing otherwise needs proper treatment.

Varies: This varies quite a bit, depending upon the cause, the treatment, the size and location of the infection, your general medical and dental health, the type of infection and your body's healing powers. Antibiotics alone do not cure the infection. The cause has to be resolved as well. Discuss this issue with the dentist who is actually treating you and should follow your progress until it's gone.

Depends: It depends on how severe the infection is, the type of bacteria implicated in the infection and if you have any health issues. Usually after a few days of antibiotics, mild tooth infections may resolve. However, the best treatment is to see an oral surgeon and get the tooth treated properly.