Amalgam fillings


What is it?

An Amalgam filling is used to restore damaged or missing tooth tissue (usually as a result of tooth decay) in premolar or molar teeth.  Amalgam is an alloy composed mainly of mercury, silver, tin, copper and zinc.

Diagram of an amalgam filling

Amalgam Filling diagram

What is it for?

When a cavity has been formed by dental decay, all the damaged and diseased tissue must be removed to prevent the decay from progressing and making the cavity larger. Once all the diseased tissue has been removed, amalgam is used to fill the resulting cavity and restore the tooth as closely as possible to its former shape and size. If left untreated, decay inevitable causes dental abscesses which may require root canal fillings or tooth extraction.

What does the procedure involve?

In most cases, the tooth will have to be numbed with a local anaesthetic before the procedure is carried out. The diseased part of the tooth is cut away, then the resulting cavity is filled with the amalgam. Amalgam does not adhere to teeth. This means the cavity holding the amalgam must be prepared with undercuts to hold the filling in place, often requiring excess healthy tooth tissue to be removed.

What are the alternative treatments?

Are amalgam fillings safe?

There are several information sources claiming that the mercury in dental amalgam can cause health problems. The best and most comprehensive studies carried out on the subject have confirmed that dental amalgams pose absolutely no threat to a patient’s general health in any way.

How long will it last?

Amalgam fillings have a long track record. Fillings placed in strong teeth under good conditions will last an average of 10-12 years. This is not a minimum – it means 50% of fillings will need further treatment by this time. Fillings may fail as a result of further tooth decay, tooth fracture, of the filling falling out, all of which may need remedial treatment.

Pros and Cons



Inexpensive  Poor appearance
Simple, quick treatment  Will not adhere to teeth
 Durable  Less conservative than composite fillings