What are the best materials for filling cavities in teeth? I was told that silver fillings should be used because the white fillings leak and need to be replaced every two years. –E.G.

Dear E.G.: While I have several "silver" fillings from years past, I would never allow a dentist to place a silver filling in one of my teeth today. Why?

Silver fillings aren't silver - they are made up of a combination of approximately 50% mercury combined with smaller amounts of silver, copper, tin, and sometimes other metals like zinc. Mercury is a toxic substance that has been removed from most products in the marketplace. While dentists and governmental agencies continue to insist that mercury amalgams are perfectly safe I find it difficult to accept their conclusion when other governmental agencies continually warn against mercury exposure.

Amalgam fillings expand as they harden, creating hairline fractures in the tooth. Those hairline fractures weaken the tooth and cause it to break later in life requiring a crown to be placed on the tooth. In contrast, composite (white) fillings bond with the tooth and contract as they cure to hold the tooth together. When they were first introduced their life expectancy was thought to be about half that of amalgam fillings, but as the technology has improved the durability has become similar to that of amalgams. When they first became available composite fillings were more costly than amalgams, but the price of composite fillings has dropped with increasing popularity and advances in technology. The difference in price for the composite filling, even if it requires replacement, pales in comparison of the cost of a crown made necessary by the damage of an amalgam filling.