What are they?
A filling is a dental restorative material used artificially to restore the function, integrity and shape of missing tooth structure. The structural loss typically results from caries or external trauma.
Which materials can be used?
Different materials can be used as fillings:
Amalgam is a mixture of mercury and silver, tin and copper which produces a mouldable mass that can be packed into a preparation before setting hard, has a silver colour and is the NHS option as fillings on the biting surfaces of back teeth. Amalgam has been used for hundreds of years as a filling material and is recommended for fillings that are used for chewing as it is durable.
Resin composite is a mixture of resin and a filler and are used as fillings in more visible areas because it is tooth coloured: front teeth, lateral side teeth which are also available on the NHS if clinically necessary (available as private treatment on back teeth).
Glass ionomer is made of a specific type of glass material. Glass ionomers release fluoride, which can help protect the tooth from further decay. However, this material is weaker than composite resin and is more susceptible to wear and prone to fracture. It is mostly used as filling for management of root caries or temporary restorations
How they are made?
The dentist will normally give you an injection to numb the area although for small fillings this may not be needed. The decay and/or old fillings are removed by drilling and then the tooth is shaped according to the filling material. A retentive cavity is required for amalgam filling so more tooth substance may need to be drilled away.
Fillings are the first choice when a small to medium size restoration is recommended; they need one appointment and are the most conservative and economic way to restore a tooth with small to medium cavities.
As fillings increase in size and the remaining tooth structure diminishes the prognosis for the tooth reduces and the potential for the failure of the restoration becomes greater. In particular, the weakness of the remaining tooth increases the risk of fracture and if the filling is deep and close to the nerve there is risk that endodontic treatment (root canal treatment) might become necessary. Deep fillings are often associated with post operative pain and sensitivity. In addition, in the case of large restorations it may be difficult to achieve a good contact point with adjacent teeth causing a food trap. In all those cases an indirect restoration (laboratory made) such as crown/inlay may be recommended.
Cost for one or more fillings on the NHS is a Band 2 charge.