Seeing the dentist


X-rays (radiography) are an important part of the dental care process. An X-ray is used as part of the diagnostic process when the image created can reveal areas that require treatment.


An X-ray is a form of high energy electromagnetic radiation from the same family as light energy. They can be absorbed, reflected or scattered. Unlike light, X-rays can penetrate objects.

There are two types of dental X-ray:

  • Intraoral – inside of your mouth
  • Extraoral – outside of your mouth.

Healthy oral tissues have different densities. While the enamel is dense and blocks X-rays, the dentine (bulk of the tooth) and roots of the tooth are less dense. The centre of the tooth (pulp) and its roots only contain soft tissues and absorb fewer X-rays.

Why are X-rays performed?

  • May show tooth decay
  • A view of the tooth roots
  • Damage to the bones supporting the teeth
  • Misplaced teeth that may need orthodontic treatment.

Types of X-ray

  • Periapical – provides a view of the whole tooth, to determine suspected disease at the root tip or problems below the gum line or jaw
  • Bitewing ­– these capture an area of up to four teeth, detecting caries (decay) or imperfect fillings or crowns
  • Occlusal – the film is placed on the biting surface of the teeth, revealing teeth that are yet to push through and cysts
  • Panoramic – shows all of your teeth and the supporting structures.