With regards to your mitral valve premedication and becoming immune to
the antibiotic.

Anyone can become "immune" or resistant to an antibiotic but which
would you like to have 1) becoming immune or 2) dying of a heart attack
2 days after your filling, deep cleaning etc...
If you have a legitamate condition that warrants premedication then you
are not in a position to worry about resistance. It becomes and is
everyone else's responsibility to make sure that antibiotic is not
overused for stupid things that your body can fight off without help.
It is not easy to come up with new antibiotics the bacteria mutate at a
much faster rate and we can not keep up with it. We have to be more
conservative with antibiotic use and use it on people that can benefit
from it's protection such as yourself.
I think your dentist did the right thing. Bruses are minor risks of
local anaesthesia and are not discussed as much because they are very
rare and heal without incident.

Alexander Vasserman DDS

    Briefly--
    I have once or twice seen severe bleeding following injection.  The
once I remember was a patient in our dental school who had had an
injection--I believe by an instructor.  I believe it was for an upper
tooth.  The patient's face blew up like a balloon.  This is something
you hear about in the textbooks, but rarely see.
    Unless you have some kind of bleeding problem or the dentist had a very
unusual injection technique, I think this is extremely unlikely to
happen again.  It has nothing to do with your mitral prolapse.

Steve

Ok, I am one of the cowards that a dentist caters to....but I found a
wonderful dentist with a GREAT personality too....
But something happened to me when he gave me the novocaine shot, first
of all he was going to pull an impacted wisdom tooth and fill a tooth
next to it, so the shot was really far back there, instantly my jaw
swelled up, as soon as he injected me, then it started to bruise, and
bruise BAD!! he said he ''hit a vessel'' and this happens
sometimes???????? (he didnt pull the tooth, just filled one)
he put me on keflix for 2 weeks because the tooth he filled was BAD and
he wanted to make sure there was not an infection under the gum...
( I do have mitra valve prolapse)
i'm taking 4 (500) mg a day, and I dont have a tooth ache, (he said I
would get a really bad tooth ache, (if it didnt hold) well, it will be 2
weeks on monday and no tooth ache,,,
I dont want to call him up, because I dont want him to think i doubt his
word!
but I was wondering if i could become immune to the antibioitc, (because
I need more dental work next week) and because of the MVP, i dont want
to become immune....
also, does this sound like what happened???
(a vessel)????? and is the bruise normal????
is there ANY concern with the brusing and the MVP??????

was this because it was SO FAR back in m mouth and he couldnt see????  

I have had novocaine in the past with no problems at all.

and whose fault was this?...was it the dentist OR my gums????
actually, I would rather think it was the dentists fault (he was in a
hurry) because then I wouldnt be scared next time, because I KNOW he
would be so careful, but if I think it's a problem with MY gum, then i'm
scared all over again...
if this was his fault, it does not change my mind about him as a dentist
because i KNOW no matter what he did not do it on purpose!!!! i still
really like him and am so glad i found him, but i just want to make
sure, I am ok (healthwise) and as I said before, I dont want to keep
calling and doubting his word...it just seems like I cant get a straight
answer there,,,it almost seems like he feels really bad that it
happened....it was my first visit with him.....maybe if someone tells me
its normal I can chill out...lol...my jaw is starting to fade (the
bruise) but it seems like it dropped to the bottom of my jaw (the
bruise)and when I press on the dark bruise there is slight pain????? is
this all normal???
its the`MVP' that scares me, appearance, does not matter,,,but the
receptionist thought i would be really mad because, I think she thinks I
might have been a pricy type....LOL.....but I really dont care about a
bruise,,,,

People did ask me ''WHAT HAPPENED'' lol..i HAD to tell what happened BUT
I never told the dentists name, I made a name up.....(if someone asked)

Thanks for reading......TIA for any input....