The mercury-free dentist does not place amalgam, period. Instead, they rely on gold, zirconia (a white, powdered metal oxide), composite (white filling), or ceramic (porcelain) alternatives. Some even go as far as to completely eliminate all metal-containing alternatives when possible.
Are the metal alternatives safe? In general, yes, especially in regards to the gold-containing alloys. Gold is hard to beat in regards to biocompatibility and lifespan. It goes downhill from there though, as the non-gold-containing metal alloys can cause allergies in some patients.
Using these metal alternatives, one can restore a tooth in a variety of ways. From least invasive to most invasive, they are inlays, onlays, and finally crowns. Many times dentists have their outsourced laboratory fabricate metal crowns with porcelain overlays.
Have you ever seen someone with a white crown smile and you can see a dark ring around the gumline? Chances are excellent that you were observing a porcelain fused to metal crown. But what kind of metal? Be sure to ask. The dentist may not be using gold alloy-based metals, but the cheaper, more allergenic base metals containing materials such as nickel instead.
The biggest problem that I see with the metal variety though, is that they are simply not minimally invasive, meaning that more tooth structure was removed than was necessary in contrast to other viable alternatives.
Dr. Nick Yiannios is a mercury-safe and mercury-free dentist in Rogers, AR.