There has been considerable concern over various filling materials – mercury in amalgam, and BPA in tooth-colored composite. From my perspective, it becomes a matter of the lesser of evils. Yes, mercury is a poison. The ADA claims the mercury is bound in a different chemical form than elemental mercury and that there is no evidence from any double-blind studies (the gold standard in research) that the mercury vapor given off from activities such as chewing is harmful to the body. Maybe, but it makes logical sense to me that if it is it is a poison before it goes into the body, and it is a poison once it leaves the mouth, why isn’t it a poison when it is in the mouth? However, if it comes down to a choice between extraction or amalgam, I’ll take amalgam any day of the week. Europe is trying to ban the substance entirely.
The chemical composition of a composite is longer than your arm. It is a much more technique sensitive product than amalgam, but if done correctly, it should last and wear equally as long as amalgam, and God knows, it looks far better. So what are your alternatives? Extraction would eliminate the concerns but gives a totally different and usually worse problem. Cast gold is still considered the “gold standard” for restorative work, but it is pricey and does not look that nice on anterior teeth. Porcelain is also pricey, technique sensitive and more prone to fracture, especially in the posterior regions of the mouth.
So, it is not a perfect world–at least with regards to dental restorative materials.
Is a composite better than amalgam? I’d say yes.
Is amalgam better than extraction? Definitely.