i would not have even mentioned Amalgam illness to her. make up a better story. tell her some fiction, doesn't matter. these people are both in total and complete denial, and the underlying fear here is that dentists could be liable to be sued. so the entire industry is in serious denial. you will get nowhere with this.
the records are yours. they aren't top secret military intelligence. call her back and demand the records. be polite, but insistent. dont take no for an answer. you have EVERY right to those records.
who knows maybe she is just lazy and doesn't feel like digging them up? stand up for yourself here. \
of course if i were you i would just get the mercury out of my mouth. who cares when you got the mercury in? just get it out. thats my advice anyway.