Why take dental x-rays?
Dentists take x-rays to assist them in seeing beneath the surface of the teeth and gums. This helps the dentist to detect diseases that may not be visible to the naked eye by a visual examination alone. The type of x-ray your dentist takes will depend on the condition for which you are being assessed.
Dental x-rays can be used to detect:
- Tooth decay.
- Issues with past dental treatment.
- Bone lost from around teeth associated with severe gum disease.
- Tooth and bone fractures following an accident or injury causing damage to the face or mouth.
- The location of teeth in relation to nerves, sinuses, and other facial structures.
- Abcesses, cysts, and tumours.
- Stages of tooth development including the timing of when teeth will push through into the mouth.
- Extra teeth, missing teeth, and teeth that are blocked from moving into the mouth, called impacted teeth.
X-rays allow dentists to plan for dental procedures, such as fillings, dental implants, orthodontic treatment, denture fabrication, root canal treatment and removing a tooth (extraction).
The safety of dentals x-rays
Both children and adults can have dental x-rays safely taken. The amount of radiation exposure involved in dental x-rays is extremely low and unlikely to cause any ill health effects.
The table in this fact sheet compares radiation exposure from dental x-rays to everyday life events. If you are pregnant and experiencing a sore tooth or other dental problems, dental x-rays can be safely taken during this time to help the dentist diagnose the problem. Your dentist may place a lead apron over your body.
Your dentist will leave the room when they take your x-rays. As a patient, you may have dental x-rays taken months to years apart, but your dentist takes multiple x-rays every day. Although dental x-rays are safe, your dentist is avoiding ongoing radiation exposure by stepping outside the treatment room.
The advice from the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) is that lead aprons are not usually (or routinely) required for dental x-rays. This is because x-ray doses are so low and well controlled in modern dentistry.
Types of dental x-rays
Bite wing x-rays
Bite wing x-rays are used as part of general dental check-ups. They are most commonly used to look for tooth decay and examine the level of bone around the teeth.
Your dentist will advise you how often these should be taken. This is usually based on how well you care for your teeth, your risk of developing tooth decay and/or gum disease, any current signs of disease and the status of your past dental treatment.
A periapical x-ray is used to view an entire tooth including the root/s of the tooth and the bone surrounding it. Some situations where your dentist may ask to take a periapical x-ray include if you have a sore tooth, before removing a tooth or before, during and after root canal treatment. Your dentist will ask for your consent to take the x-ray and should explain the reason it is needed.
A panoramic x-ray, which you may hear your dentist refer to as a ‘full-mouth x-ray’. This type of dental x-ray includes a view of the temporomandibular (jaw) joints (TMJ), eye sockets, maxillary sinuses, bones of the maxillary (upper) and mandibular (lower) jaws and the teeth. Full-mouth dental x-rays allow dentists to:
- Detect conditions such as cysts, tumours, and infections.
- Assess the severity of gum disease.
- Assess the stages of tooth development in children.
- Review the development and location of wisdom teeth.
- View how close the teeth sit to nerves, maxillary sinuses, and other facial structures.
- Make plans for dental procedures.
These x-rays provide a good overall view of your mouth. Your dentist may also ask to take additional x-rays of areas of the mouth they need to inspect closer. Generally, full-mouth x-rays are not recommended as the main x-ray to be used for detecting tooth decay.
Lateral cephalometric x-ray
A lateral cephalometric x-ray is used to capture a side-on view of your head and neck. This x-ray, together with a full-mouth x-ray, are routinely used in planning orthodontic treatment.
Cone beam computerised tomography
Cone beam computerised tomography (CBCT) is used to create a three-dimensional (3-D) image of your teeth, jaws and surrounding facial structures. It may be referred to in short as a CBCT. These x-rays are commonly used by dentists and dental specialists when planning more complex treatments.
Not all dental practices will have the equipment to take all the above listed types of x-rays.
Where necessary, you may be provided with a referral to an x-ray clinic that has the necessary equipment to take the required x-ray.