How long does it take for antibiotics to relieve pain from tooth infection after filling?

Antibiotics: Antibiotics are not pain relievers... They are antibiotics (they kill bacteria). If you have an infection from a nerve that has gone bad, expect 24 to 72 hours before you start feeling relief. In the meantime take pain meds to help manage your pain.

24 to 72 hours: Antibiotics can start providing relief anywhere from 24 to 72 hours. If you don't have any relief by 72 hours you should call your dentist as you might need a different antibiotic or an emergency dental treatment. For temporary relief you can take OTC NSAIDs or Tylenol (acetaminophen). The only way to cure a dental infection is with dental treatment.