Hi BC,
I work for a dentist, & some of our patients have forgotten to take their med's so when they get to the office we just give it to them there. You are suppossed to take the antibiotics to avoid getting Bacterial endocarditis. Dental procedures can cause bacteria to get into the blood stream causing this condition. While we have never had a patient become ill from this, I have heard of patients expiring from not taking their med's. I do not think the odd's are to high that something will happen, but to be safe just make sure you take your antibiotics. We make our patients take 4 pills 1 hour prior to coming in for their appointment.