What Are The Alternatives To Mercury Amalgam?

Mercury amalgam is used as a dental filling because it's a decent compromise (ignoring the possible health risks) compared to other filling materials.  It lasts 20-30 years (typically).  It's not to expensive.  It's easy for dentists to work with and quick to apply.

The main alternatives are gold or resin composites.  Gold lasts very well and is very safe in the human body, but is also very expensive.  It also shows up quite a lot when you smile, That may or may not be to your taste.

Resin composite fillings (sometimes called 'white fillings') are expoxy (glue) based mixed with silicates (typically).  This combination isn't necessarily that much safer than mercury (not absoltuely proven as safe, anyway).  Resin composite takes longer than amalgam to apply, and doesn't last as long as amalgam (typically only 10 years, so have to be replaced after that).  White fillings are better in visible places (front of your teeth), and they require less of the decayed tooth to be drilled out.