I have an infection under my crown. how long should it take antibiotics to start working & can i take painkillers alongside these?

Yes: Yes you can take pain medication with antibiotics . Depending on the severity of the infection and the susceptibility if the bacteria to the antibiotics you are taking ( some will not work at all j) it should take several days to feel a difference but you need to keep taking them as prescribed.. The pain you are experiencing can be managed with anti inflamitories like motrin.

Yes: But do not self treat! abscesses must be treated by a dentist. Meds do not cure your problem, they just keep it bay until a dr. Treats.It usually takes 24-48 hrs for antibiotics to kick in. Antibiotics won't remove the abscess, they simply decrease the buildup of puss, hence decreasing pain.