There are three main kinds of restorative filling material. Amalgam fillings also known as silver fillings, composite (tooth like) white filling material and glass ionomer white filling material. All can be used to restore a tooth.
Dental amalgam is a dental filling material used to fill tooth cavities and has been used for more than 150 years in hundreds of millions of patients.
Dental amalgam is a mixture of metals, consisting of liquid mercury and a powdered alloy composed of silver, tin, and copper. Approximately 50% of dental amalgam is elemental mercury by weight.
Dental amalgam fillings are also known as “silver fillings” because of their silver-like appearance.
When placing dental amalgam, the dentist first drills the tooth to remove the decay and then shapes the tooth cavity for placement of the amalgam filling. Next, under appropriate safety conditions, the dentist mixes the powdered alloy with the liquid mercury to form an amalgam putty, this comes in capsule form.
Tooth-coloured fillings that are designed to match the colour of your teeth are called composites. Composites are a mixture of glass or quartz filler that provide good durability and resistance to fracture in small- to mid-size restorations that need to withstand moderate pressure from chewing. They are generally used on either front or back teeth.
Composites are "bonded" or adhered in a cavity. This can allow your dentist to make a more conservative repair to your tooth, meaning less tooth structure is removed when the dentist prepares the tooth. Ir generally takes longer to place a composite filling than a metal filling. This is because composite filling require the tooth the be kept clean and dry while the filling material is being placed. You can eat and drink on the tooth straight after as its cured with a light throughout the placing of the filling so its fully set and ready for use.
Glass Ionomer Fillings
Glass Ionomer Fillings are a material made from acrylic and a component of glass – ‘flouroaluminosilicate’. They can be bonded to your tooth using chemical reaction which makes the bond very strong.
The filling is bonded straight onto the tooth, Glass ionomer fillings are not as hard wearing as composite or amalgam fillings so they tend to be used to restore cavities in children and babies or as a temporary filling. The can always be used around the neck of the teeth where they will be no bite pressure.