Dental x-rays- What are they for and are they safe?
Dr Oh Xue Ling BDS (Adelaide)

A visit to the dentist typically involves getting X-rays done. However, many are hesitant to have X-rays taken for various reasons such as safety concerns, cost, and discomfort. These X-rays are commonly used as diagnostic tools and are essential in ensuring that you get a good and thorough checkup.
When an X-ray is taken, it will travel through the mouth, and onto the x-ray film. Dense objects such as teeth and bones will show up as light-coloured, whereas less dense objects such as gums and cheeks will appear as dark-coloured. From this, we will be able to check for things such as:
- Decay
- Bone loss due to gum disease
- Impacted teeth
- Wisdom teeth
- Infections at the root of teeth or in between teeth
- Cysts, tumours
- Development of teeth (for children)
What are the different types of dental X-rays?
There are two main types of x-rays taken in a dental clinic: intraoral and extraoral.
Intraoral x-rays are taken with an x-ray film placed inside the mouth and are used to show localized areas of the mouth. They are commonly taken to detect any decay, monitor bone height, and for certain dental procedures such as root canal treatment.

Extraoral x-rays are taken with the X-ray film outside of the mouth. These are commonly used to detect problems in the jaw and/or skull. There are many types of extraoral x-rays, including CT scans which allow the dentist to evaluate the jaw and skull in three dimensions.
How often do I need X-rays and when do I need them?
This differs from person to person and is based on several other factors such as age, your condition, and dental history. X-rays may be taken regularly every few years as a part of a thorough examination. For individuals who are more prone to decay, they may be needed more regularly than others. Certain procedures also require the use of X-rays, such as root canal treatment, planning for orthodontic treatment (e.g. braces), and implants.
However, if you are pregnant, you should always inform us before taking any X-rays. Although the radiation dose is small, it is still advisable to delay if it is not urgent.
Are dental X-rays safe?
Contrary to what most people believe, the radiation from a dental x-ray is much lesser than what they perceive it to be. In fact, with modern X-ray technology, exposure to radiation has been greatly reduced as compared to before. A series of 4 small intraoral dental x-rays taken would amount to approximately 0.005mSv, which is comparable to one day of natural background radiation, or a 1-2 hour short plane flight. Interestingly, bananas are radioactive as well; a dental x-ray will amount to about 50 bananas in terms of radiation levels. If you’re not afraid of eating bananas, neither should you be afraid of taking dental x-rays!