General information only. This article explains dental topics in general terms and isn’t a substitute for personal advice. Everyone’s oral health and dental needs are different, so please see a dentist for advice that applies to you.

Digital X-rays use an electronic sensor instead of film to capture images of the teeth, gums and jaw. The image appears on a computer screen within seconds. This article explains how they work, how they compare with film, what they show, how safe they are and how often they are taken.

How digital X-rays work

A small sensor, or a phosphor plate that is scanned afterwards, is placed in the mouth or, for a panoramic X-ray, the machine rotates around the head. A brief, low-dose X-ray exposure creates the image, which software displays straight away. No chemical processing or darkroom is needed.

Types of dental X-rays

Bitewings show the back teeth from crown to just below the gum line and are used to find decay between teeth and check bone levels.
Periapicals show one or two whole teeth, including the root tips, to look for infection or other problems.
Panoramic X-rays (OPGs) show both jaws, all the teeth and the jaw joints in one image, useful for wisdom teeth and general assessment.
3D scans (CBCT) are a different type of X-ray that gives a three-dimensional image for more complex cases. See CBCT scans in dentistry.

Advantages over film

Speed: images are ready almost immediately, so they can be discussed during the same visit.
Image tools: brightness, contrast and zoom can be adjusted on screen to examine an area closely.
Lower dose: digital sensors are more sensitive than film, so they generally need less radiation for a similar image.
Storage and sharing: images are stored securely with your records and can be sent electronically if you are referred to another practitioner.
No processing chemicals to handle or dispose of.

What X-rays can show

X-rays help find problems that cannot be seen during an examination, such as decay between teeth or under fillings, infection at the root tip, bone loss from gum disease, impacted or missing teeth, cysts and some other changes in the jaw. Finding these early usually means simpler treatment.

Safety

The radiation dose from a small dental X-ray is very low, comparable to a small fraction of the natural background radiation we all receive each year. Even so, X-rays are only taken when they are likely to help with diagnosis or treatment, following the principle of keeping doses as low as reasonably achievable. Tell the dentist if you are or may be pregnant; X-rays can often be postponed, or taken with extra precautions if needed.

How often X-rays are taken

There is no fixed schedule. How often X-rays are needed depends on your age, your risk of decay and gum disease, and any symptoms. Someone with healthy teeth and low risk may need bitewings only every couple of years, while someone with frequent decay or gum problems may need them more often.

Developments to watch

Software, including artificial intelligence tools, is being developed to help highlight possible problems on X-rays. These tools can support but not replace the dentist’s assessment.

Common questions

Do digital X-rays hurt?

No. Some people find the sensor slightly uncomfortable to bite on, but it only takes a few seconds.

Can I get a copy of my X-rays?

Yes. You can ask for copies, for example if you are seeing another practitioner.