Fillings are used to fill holes (cavities) that have formed, usually as a result of decay or tooth wear. There are many types of filling, each suitable for different cavities.

Most people have a local anaesthetic injection to completely numb the area while the filling is being done. The numbness can take several hours to wear off.

The decayed and weakened parts of the tooth are removed using small drills and the hole is washed.

If the hole has spread to the side wall of the tooth, a band will be placed around the tooth with a small wedge holding it in place. This ensures that the filling hardens into the correct shape.

To protect the tiny nerves and blood vessels inside the tooth, very thin layers of underlinings, such as resin, are painted inside the hole before the filling material is packed in. The filling will begin to harden during the first few minutes or, for some materials, a blue light is used to make it set within a few seconds.

Sometimes temporary fillings are used where there may not be enough time to do the full treatment, at emergency appointments for example. Temporary fillings can last for quite a long time, but they are not very strong so you must always arrange to have a durable filling placed within a few weeks.
Amalgam fillings

Amalgam fillings are made of a combination of metals including silver, tin, copper and mercury. The advantage of using amalgam is that it's extremely durable and able to withstand the grinding and chewing of the molar teeth over long periods of time.
Tooth coloured fillings

Tooth coloured fillings can be chosen to match the colour of the teeth, making them a natural-looking alternative to amalgam fillings.

Tooth coloured fillings are often used in teeth that show during smiling or talking. They aren't as durable as amalgam, and so they aren't always suitable for the grinding and chewing surfaces of the back teeth.

There are a few different types of tooth coloured filling materials. The most common are called composite and glass ionomer. They are soft and can be moulded to look like the shape of a tooth before they are hardened, usually using a blue light. Tooth coloured filling materials stick to teeth, so they can be used to build up the edges of chipped or worn teeth.

Composite shrinks very slightly under the blue light. This can pull on the tooth and may cause sensitivity. It can also produce a tiny gap between the filling and the tooth that may lead to further decay.