I think I'm that friend that A and C's mum was talking about. :)
Had 2 of my wisdom teeth out on Thursday, I am BF my 2 daughters and the anesthetic they give you is fine for Bf mums. It does pass into the breastmilk but in very small quantities. My 2 are not newborns, although DD2 is a similar age to your youngest sbeach and she has been fine with it, no side affects at all.