Worry about radiation is one of the most common reasons people hesitate about dental X-rays. It is a fair question, but the numbers are reassuring. A single digital bitewing X-ray delivers roughly 0.005 millisieverts of radiation. To put that in context, the average person in Australia absorbs around 1.7 millisieverts a year just from natural background radiation, and a few hours on a plane adds a similar dose to a dental film. A routine dental X-ray is closer to a day or two of ordinary living than to anything dramatic.
That does not mean X-rays should be taken casually. The guiding principle dentists use is to take them only when the clinical benefit justifies it, and to keep the dose as low as reasonably achievable.
Key takeaways
- A digital dental X-ray uses a very small dose, comparable to a day or two of natural background radiation.
- Digital sensors use significantly less radiation than the old film X-rays.
- X-rays reveal decay between teeth, bone loss, infections, and other problems that cannot be seen by eye.
- How often you need them depends on your risk, not a fixed schedule. Low-risk adults may go two years or more between sets.
- X-rays in pregnancy are generally avoided unless necessary, and shielding is used when they are needed.
Why dentists take X-rays at all
About a third of each tooth sits below the gum, and the surfaces where teeth touch are hidden from direct view. X-rays let your dentist see what an examination alone cannot. They reveal decay starting between teeth, infection at the root tip, bone loss from gum disease, cysts, impacted wisdom teeth, and the position of developing teeth in children. Catching these early usually means simpler, less costly treatment. A small cavity found on a bitewing might need a simple filling, whereas the same cavity found two years later by symptoms might need a crown or root canal.
Types of dental X-ray and their doses
| Type | What it shows | Approx. dose |
|---|---|---|
| Bitewing | Decay between back teeth, early bone loss | ~0.005 mSv |
| Panoramic (OPG) | Whole jaw, wisdom teeth, sinuses | ~0.025 mSv |
| CBCT (3D scan) | 3D view for implants and complex cases | ~0.05 to 0.1 mSv |
For comparison, a four-hour flight gives you roughly 0.02 to 0.05 millisieverts. Even a 3D scan, the highest-dose dental image, sits within the range of everyday exposures.
How often should you have them?
There is no one-size-fits-all schedule, and good practice is to base frequency on your individual risk rather than a calendar rule. As a general guide:
- Low-risk adults with healthy teeth and gums may only need bitewings every 18 to 24 months, sometimes longer.
- Higher-risk patients, including those with active decay, gum disease, dry mouth, or a history of frequent cavities, may need them every 6 to 12 months.
- Children may need them a little more often during the cavity-prone years, as decay can spread faster in baby teeth.
- New patients often have a baseline set so the dentist can see what is happening below the surface from the start.
If you have recently had X-rays elsewhere, ask for copies. A good dentist will not repeat imaging unnecessarily.
Are dental X-rays safe in pregnancy?
Routine X-rays are usually postponed during pregnancy as a precaution, even though the dose to the abdomen from a dental film is extremely low. If an X-ray is genuinely needed, for example to diagnose a painful infection, it can be done safely with lead shielding. Always tell your dentist if you are or might be pregnant. Our pregnancy dental care guide covers this in more detail.
How dentists keep the dose low
Modern practice minimises exposure in several ways: digital sensors that need a fraction of the radiation of old film, lead aprons and thyroid collars where appropriate, careful beam aiming, and the simple discipline of only taking an image when it will change the diagnosis or treatment. The benefit of finding a hidden problem early almost always outweighs the very small radiation involved.
Frequently asked questions
How much radiation is in a dental X-ray?
A digital bitewing is about 0.005 millisieverts, similar to a day or two of natural background radiation or a short domestic flight. It is a very low dose.
Do I have to have X-rays if I do not want them?
You can decline, but be aware that your dentist may not be able to detect decay between teeth or bone loss without them. It is worth discussing your concerns rather than simply refusing.
Are digital X-rays safer than film?
They use considerably less radiation than traditional film and give an instant image that can be enhanced on screen, so they are both lower dose and more useful.
Can I have a dental X-ray while breastfeeding?
Yes. Dental X-rays do not affect breast milk, so there is no need to pause feeding.
How often do children need dental X-rays?
It depends on their decay risk. Some children need them yearly during cavity-prone years, while low-risk children need them less often. Your dentist will advise.
If you are due for a check-up, our team at Lumi Dental in Melrose Park uses low-dose digital imaging and only takes X-rays when they will genuinely help. Book a check-up or see current offers.
