Hi Lisa,
Regarding your question about child sedation, there was an excellent
review of literature in a Breastfeeding Abstracts last year related
to human milk as a clear liquid.  In that review, it is considered
safe to nurse up to 3 hours before anesthesia when the medical orders
say clear liquids only.  If your dentist has said NPO - *nothing* by
mouth after midnight, then clarify if that includes clear liquids.
It would be awfully hard to keep a 2 1/2 year old calm and peaceful
if he wakes up at 6am and can't have water or mommy.
HOpe this helps.
Jeanne Fisher
Austin, TX