RUN. Silver means mercury btw. It's an amalgam, which is 50% mercury and the rest is tin, copper, silver, palladium, etc. It constantly releases mercury at room temperature as elemental Hg (mercury) vaporizes at that temperature. It's absorbed through the lungs and also through the GI tract as well as the cells around your oral cavity and nerves in the faces which are in close proximity to the brain.
If you knew what some people were going through both financially and physically to get the Amalgams removed, it wouldn't even be a question. The only reason why the dentist says that is because he is taught that at school and that idea is still backed by the ADA and FDA which numerous phDs, MDs, DMDs, DDSs, have been fighting year after year. Unfortunately, they cannot admit to it because of the sheer number of people who have already gotten them in their mouth. There's enough evidence, studies, articles, stories, journal publications that it is common sense not to have these in the mouth and yet it is still a fight. Dont do it.
Get composite. Ive had composite for years and they are better.