Most dental schools still encourage the routine placement of amalgam fillings instead of the newer white composite. Here is a comparison of the two materials:
- White fillings require less drilling away of healthy tooth structure. Amalgam fillings need to be at least two millimeters deep to be strong enough to resist biting forces. Since composite bonds to the tooth structure, it gets strength from the tooth, so it can be much more shallow. The dentist just has to drill away the decay, which means the filling is generally much smaller.
- Silver amalgam is metal, and conducts heat and cold to the inner part of the tooth. So a new amalgam filling can be quite sensitive for several weeks. Composite, on the other hand, insulates the tooth, and if properly bonded is very gentle to the tooth. Thus white fillings provoke much less sensitivity than amalgams.
- Many people don’t like amalgam showing in their mouth, even in the back. As it corrodes, it turns black.
- An advantage to the amalgam is that it is easier to place, making it cheaper. White fillings require that the tooth be kept completely dry and isolated from saliva in order to bond to the tooth. The techniques involved can be tricky for some dentists, especially if they haven’t pursued the advanced training after dental school that is generally required to master the placement of composite restorations on back teeth.
- Amalgam is actually about 50 percent mercury. Many people are concerned over the safety of placing mercury-containing restorations in the mouth, because mercury is a toxic metal that causes nerve disorders. Dr. Thein is a mercury-free dentist.
Pictures of White Fillings
These amalgams not only have turned black, but the restoration on the molar has cracked in one place, and in another place the restoration is badly corroded and appears to be leaking.