Maybe you could check with a pharmacist about the antibiotics you are going to take? I talked to a pharmacist friend about this recently and she advised that most antibiotics are breastfeeding safe... but do check with your pharmacist on your particular antibiotic to be safe.
As for breastfeeding after the surgery, I doubt you will need to stop at all! This article may help explain:
kellymom.com :: Dental Work and Breastfeeding