Fillings are needed when the tooth has either been affected by decay, is broken, or has some developmental anomaly. As well as restoring function, fillings can be natural looking as well. Many people do not want silver fillings that contain mercury, to show when they laugh or smile, as they are maybe considered aesthetically undesirable.
White fillings are made from a composite resin material that comes in different tooth shades, to look like a natural tooth. They can also be used to restore small gaps in teeth, and used in reshaping teeth.
The benefits of dental composites, is that they are tooth coloured and hence aesthetically more pleasing. Furthermore, unlike metal fillings white fillings are adhesive to the tooth, which results in more tooth preservation during preparation. The capability to expand reduces stresses on teeth.