Traditionally, silver amalgam fillings have the best track record of holding up the longest. But the white composite filling materials have been getting better and better. (Dentists no longer use gold foil to fill teeth because it is significantly more expensive and time consuming.)
Both composite and amalgam are excellent filling materials with long track records behind them. And both have their advantages and disadvantages.
Composite is a mixture of plastic and glass which must be bonded to the tooth to be successful. Because of that, they take longer to place and are more sensitive to moisture, which interferes with bonding. They are more esthetic than silver.
In small areas of decay, they don’t require as much tooth preparation. And bonding them to the tooth actually helps the tooth regain some of its lost strength. But they are more expensive than silver. And composite is not a good option in areas that are difficult to isolate and keep dry, like underneath the gumline or way back in some people’s mouths.
Amalgam is made of mercury, silver, copper and tin, which all get mixed together to form an alloy. It is relatively easy to place and, being metal, it is very strong. The main advantage to amalgam is that it is less expensive. It is not as esthetic as composite and even though we bond our silver fillings in adults, it does not bond as well.
Some people are concerned about the mercury in amalgam fillings.
- Mercury by itself is toxic. But when it is in a tooth, it is mostly bound to the other elements, and any vapor which can be measured is dramatically below what is considered safe levels.
- There is slightly more exposure to it when the fillings are place or removed, so those most exposed to mercury are dentists and assistants.
It is the most widely studied material we have in dentistry and the vast majority of scientific evidence supports it as safe and effective. Still, it is being used less and less because people want esthetic tooth colored fillings.
In most cases, we let you choose what works best for you. They’re both good materials, proven to be safe and effective. It’s up to you!
Below are Yamamoto and Lee patients with a silver and a white filling.