you need to get a copy of the NHANES III. it was done by the government and is complete. they found a causal link to many health problems and all was documented. they dotted their i's and crossed their t's. scientific methodology was used. if you read the study in it's entirety, you will see that. and, yes, they did compare those with and without fillings. do you realize you are arguing with the government, the same ones who you believe are putting non-harmful fillings in people by using mercury? anyway, your mindset is that there couldn't possibly be any scientific studies showing mercury causes disease. if you don't get out of that mindset, you will not learn anything. the fact is there are many and i have given you quite a few.
The National Health and Nutrition Examination Surveys (NHANES), conducted by the National Center for Health Statistics, Centers for Disease Control (NCHS/CDC), are designed to assess the health and nutritional status of adults and children in the United States through interviews and direct physical examinations. Here are materials related to the second and third National Health and Nutrition Examination Surveys (NHANES II and III), carried out during the years 1976-1980 and 1988-1994, respectively.