That is a difficult question to answer. To be sympomless would have to mean being in absolute perfect health. If someone has amalgam fillings and only suffers from =ocasional headaches or dairy intolerance, then they might seem to be totally unaffected by the mercury released into their systems, but in actuality they are exhibiting symptoms of very low level poisoning.

If someone has migraine attacks occasionally (accompanied by visual disturbances) then they are exhibiting symptoms of being more strongly poisoned, but also would appear to be "fine" otherwise. Then there are women who have irregular periods, who might be told it's "normal" (like I was) or people just accepting their various medical annoyances (like allergies or pins and needles in the night or floaters) are just "normal" when really are signs of poisoning.

So, I'd say it's hard to say how many people who have fillings are "normal", because mercury affects so many systems that it may be causing things they don't even think about - aswell as not thinking about the effect on personality i.e. shyness, anxiety levels, depression.

But, to be as concise as possible, yes some people have amalgams and don't appear to have any problems from them. Those of us who have a lot of symptoms are said to be more sensitive to mercury, for various reasons i.e. we are just sensitive, or we don't excrete toxins very well, or both. Some people seem to have a high tolerance to toxins, which means they seem to be ok with amalgams or high consumption of fish, or to work with heavy metals.

To put amalgam into people teeth, not knowing the effect it will have, whether it will have no noticeable one or will cause mental illness (as in my case) or give people MS, is highly irresponsible of dentists, and I totally believe should be banned.