No one has an allergy to mercury.
Don't even consider falling for that one.
The new language in traditional dentistry is that anyone who suffers from mercury poisoning caused by dental fillings is now determined to be "allergic" to mercury. This is the new code to deflect any responsibility by the dentist or the American Dental Association for poisoning you with mercury fillings.
Do not be fooled and do not be quiet. Mercury is a deadly poison. The toxicity level is second only to plutonium. With that said, if I died from nuclear fallout, would you consider that an allergy to plutonium?