hello!
i am very sorry for your bad experience. you sound like a great patient, cavity free until 22! impressive :)
i had my first one filled at 11, and i cried. not because it hurt, but because i wanted to be cavity free!
i have a feeling this may be a one time occurrence since you stated you had a new hygienist and have never had a problem at this office before. sometimes offices even hire temps if someone is sick and i've heard that some temps may not be as 'nice' as the usual staff. i would recommend asking for a hygienist you had in the past that you had no concerns with.
however there are some other possible reasons for bleeding besides a rough hygienist. such as gingivitis, medications, birth control or it being around that time of the month. hormone changes can cause bleeding in a healthy looking mouth.
a 2nd opinion is always a good idea for any dental work you may be questioning.
did you have x-rays at your last cleaning or this one? a dentist usually can't determine if a root canal needs to be done without an x-ray.
it can take a while for some cavities to form, anywhere from 6-9 months, because of this it's possible to not have any cavities at once visit and the next time have multiple. but the dentist should be able to show you your last cavity free x-rays and the current one so you can see the difference. http://www.animated-teeth.com/tooth_decay/t3_tooth_decay_remineralization.htm
it is also possible for teeth to have tiny tiny cracks in them and for bacteria to go into the cracks and cause a problem with the nerve which would then need a root canal.
but like the person before me said, was this the same tooth you had the filling on before? sometimes teeth don't 'settle down' after fillings or if it close to the nerve, the nerve just gets irritated. http://www.animated-teeth.com/root_canal/t3_root_canal_reasons.htm
there are many scenarios to this however the dentist and/or hygienist should have taken the time to explain the cause for the problem so both you and your mother could understand what happened between now and your last cleaning to necessitate a root canal on someone who was told takes very good care of their teeth.
if you like your dentist and trust him i'd set up a consultation appointment to look over the x-rays and have him explain it to you. it's your right as a patient to be fully aware of your options and understand everything before going through with the procedure.
i know very little about sedation except for oral sedation and nitrous oxide which is only an analgesic (dulls pain). dentists cannot do IV sedation unless they are also an anesthesiologist. are you going to a specialist or are you going to take oral sedation like Valium? oral sedation won't knock you out, just make you feel like you've had a few drinks and maybe a little tired. it lasts about 4-6 hours depending on what you take and how much.
http://www.dental--health.com/faq_sedation.html
please let us know how everything goes :)
-michelle