I had nine fillings for 40 some-odd years and suffered no ill effects. However, after so much time, as was explained to me by my dentist, the amalgam, which is packed into the tooth under pressure, eventually causes microscopic cracks in the tooth which can fill with bacteria and cause another cavity or worse. i had all of my fillings replaced with composite, which actually serves to hold the tooth together (as in epoxy). The cracks caused by the amalgam were visible on x-rays.
I don’t think so. I’ve had my “silver” fillings for decades, and I have a lot more than 9 of them. The worst that happens is that eventually they get loose, and have to be replaced. IMHO (yeah, I know it’s not that forum) it’s simply a money-maker for dentists to claim that OMG suddenly everyone’s being poisoned by their fillings.