S.M.
I'd definitely get a second opinion (& maybe a third); not because I doubt your dentist, but because this is a pretty serious procedure to be performing on a 3 year old. Both my 2 and 4 year old LOVE going to the dentist and I wouldn't mind keeping it that way... though not at the expense of their health. I'd *think* (no medical school in my past, so there's nothing more than a lot of pre-med classes and personal experience to give weight to what may be the advice of a ya-hoo) that a good shot of antibiotics might well take care of things.
Our pediatric dentist is pretty cool and seems very well informed (& our youngest is an *expert* at whacking the heck out of his now very chipped up baby teeth). I'd give a call -
James G Bennett, Jr., DMD - Pediatric Dentist
5458 Town Center Road Suite 16
Boca Raton, FL 33486
Ph: ###-###-####
He really cares about the kids (saw our tooth chipper the first few times for free, since he wasn't on insurance yet).
-Scott (S.'s Hubby)