At the dentist office they gave me a California Dental Facts Sheet with a list of materials that included amalgam,plastic-resin, porcelain, alloys, nickel, glass, etc.It often said, "Generally safe,....no DOCUMENTED cases of adverse affects or toxcicty".....time and again no DOCUMENTED was the term used. Kind of disturbed me, because if the medical profession knew everything obviously every time I or anyone else went to a hospital or doctors office, they'd find what caused your symptoms, and send you home well. Not that easy or simple, ...I am just beginning to believe that I personally have some kind of allergic bodily response to metal in my system that gets me ill.Yet, it hasn't been "documented".My only documentation is a myriad of horrible symptoms, and various trips to the ER and doctors offices at age 33.