Radiographs allow the dentist to see the inside of the teeth and bone. Areas which have been destroyed by decay or infection will appear as dark shadows.

Most patients know radiographs by the name 'x-rays'. In fact x-rays are invisible and are produced by the x-ray unit. The inside of this is very similiar to a television except that the x-rays produced are more powerful. This film which is placed in the patients mouth in a small packet is the 'radiograph'. The film used is very similiar to that used in normal everyday cameras except that is is black and white.

This radiograph illustrates a healthy tooth. The enamel is white, the dentin is a light grey and the pulp/nerve chamber is a dark grey. The bone is a similiar colour to the dentin and between the tooth and the bone there is a thin dark grey line which is the space occupied by the periodontal ligament.
This tooth is decayed as a dark shadow is visible on the top surface and just beneath it. A complete break in the enamel is observed and the undermining of enamel can be seen within the dentin.