As you have pain and infection in your teeth it will be better to take antibiotics for 3 day course, this is given so that if the dentist is planning any procedure as Root Canal Treatment or Extraction of the tooth, the anaesthesia will work properly there.
If the infection has not subsided chances are that you may experience pain during the treatment, but if you have already taken antibiotics the pain may not be there and your procedure will go on smoothly and be successful too.
Next Steps
if the dentist has prescribed you antibiotics prior to any procedure, you must surely complete this couse and move ahead for the treatment.
Health Tips
The tooth ache will only resolve with antibiotics and proper treatment as it will subside the infection gradually.