A variety of research studies have shown that the levels of mercury in people who have amalgam fillings are well below the point at which mercury may cause health problems. That was found to be true even in those who had multiple amalgam fillings, some with as many as 15 fillings. No evidence exists that shows amalgam fillings increase the risk for health problems. So unless you’re having trouble with your fillings or experience an allergic reaction to the material in amalgam fillings, there’s no need to have them replaced.
It is possible that over long periods of time, usually several decades or more, amalgam fillings may not hold their original shape. If the fillings become deformed, then they need to be replaced. They also should be replaced if they start to break down over time.
The bottom line is that there’s no need for concern about the safety of amalgam fillings. There is no evidence that shows any correlation between having amalgam fillings and increased risks for illness or developmental problems. Amalgam is an excellent, long-lasting material for fillings. If you have concerns about your fillings, or if you experience problems with them, talk to your dentist about the need for replacement. — Thomas Salinas, D.D.S., Dental Specialties, Mayo Clinic, Rochester, Minn.