Ok, I have a friend who went under general for a breast enlargement operation (i suppose you didn't need that much info, but I just wanted to say it) but anyway, I'm not sure if she'd had any pills the weekend previous (i'd pretty much say she didn't she's pretty sensible like that) BUT she does go pretty hard normally, she's had heaps of pills in the past.
Anyway, my point is, that the op went fine but she took ages to come out of the general, and I think she took more to be put under. Because of all this, the first thing they asked her when she woke was "do you take illicit substances on a regular basis?" she said no (silly girl should have said yes to find out why they asked) and I heard nothing further.
My advice would be to just tell your dentist/doctor the deal. They know best (??) and while they'll probably tell you not to do pills the weekend before (just because they kind of 'should' - regardless of whether its necessary or not) you might strike it lucky and find that your doctor will be honest with you and tell you the proper deal. did that make sense?
Chances are pills before op COULD be dangerous, but even if they're not your Doc will still probably tell you they will be.
*nod*
have you posted this to the medical forum?