A good dental patient is an informed patient. People can become much better informed dental patients by knowing how to read dental x-rays.
Haven’t you ever wondered what your dentist was referring to when she pointed to some part of an x-ray, saying “see, right here?” expecting you to understand completely? For you, it might as well have been a map of Antarctica!
This article will help you gain some of the background you need to look at—and understand—your dental x-rays when they’re shown to you.
Dental X-Rays: The Basic Types
The most basic function of a dental x-ray (also called a radiograph) is to spot tooth decay and potential or existing cavities (caries). It’s also to check for any progression of problems noted in earlier x-rays.
In this section, we’ll introduce five common types of dental radiographs.
Bitewing
This is the most common type of radiograph. It shows the teeth above the gum line and the height of the bone between the teeth.
Bitewing radiographs help identify and diagnose gum disease and cavities between teeth. Normally, four bitewings are taken as a set that, together, show all the teeth in someone’s mouth
Full Set
This is a comprehensive radiograph that captures images of all the teeth and surrounding bone. Along with diagnosing cavities, the full set can identify cysts or tumours, abscesses, impacted teeth, and gum disease.
Panorex
With a panorex radiograph, you sit still while the X-ray head rotates around your lower face providing a single large image of your jaws and teeth.
This type of x-ray reveals more than the others described so far, including a good view of any impacted teeth.
Periapical (PA)
This is a single x-ray focusing on a specific area of concern—for example, where you’re complaining of a bad toothache.
Cone Beam Computed Tomography (CBCT) or 3-Dimensional X-Rays
This is the remarkable result of new technologies in dentistry and radiography. CBCT “uses rotating x-ray equipment, combined with a digital computer, to capture clear, coloured 3-dimensional pictures of soft tissue, bone, muscle, and blood vessels.”
How to Read Dental X-Rays
With traditional dental x-rays, all images are produced on black and white film. Here’s what to look for:
Dark Spots or Lines
These can indicate tooth decay in progress—it’s a change in tooth density but it hasn’t yet turned into cavities.
A Deep, Dark Line Between Teeth
This indicates the early formation of cavities between the teeth (instead of in molars, where they’re somewhat more common).
A Dark Halo Around a Tooth
This is the sign of an abscess.
A Dark Hole Shape
This is likely the sign of a cyst in the mouth. Cysts can be harmless or become infected and therefore highly problematic.
A Very Bright Area
This shows an existing metal (amalgam) tooth filling.
A Notch on the Side of a Tooth
This is a lesion that signals future decay.
The Lightest Colour
This is typically the (healthy) tooth enamel.
There are a lot more things to discover in a dental x-ray, but we’ve shared enough here to pique your curiosity. If you’re interested, many annotated sample x-rays can be found in the links included here.
Ask Your Dentist!
Dentists are nearly always eager to answer your questions, including by explaining what dental x-rays show. So, don’t hesitate to ask whenever you’re curious about something you notice or we point out. This is our job after all.
We believe that the more patients understand their dental health, the more likely they are to be conscientious in caring for their oral health.
After reading this article, our Dental Team at Estrabillo Dental Group hope you’ll consider visiting us for your next dental check-up—and x-ray! Just let us know when you might be able to come by for an appointment in our office.
