For Patients: How Does Cone Beam CT Work, and Why to Find a Dentist Who Uses this Technology

If you ever meet a dentist who really geeks out over their work like me, you will hear us talking about how awesome CBCT technology is. But what is cone beam technology, and how does a cone beam CT work?

Let’s explore… with a real-life tooth story, of course!

How Does Cone Beam CT Work?

Before we dive into the tooth story, let’s talk about the technology. CBCT stands for cone beam computed tomography, so you might hear it called a cone beam or cone beam CT.

The beam from the machine is literally in the shape of a cone. The beam moves in a pendulum type movement in 360 degrees around your head. This gives your dentist a super-powerful three-dimensional image of your mouth, so they can see what’s going on in your teeth, slice by slice.

You’ll be happy to know that CBCT has a waaaaaaay smaller radiation dose than a traditional medical CT machine (150x to 200x less radiation). So they are extremely safe, and their benefits are absolutely huge!

Cone Beam CT Can Help Your Dentist Diagnose You Correctly

Sometimes, traditional imaging (like x-rays) are inconclusive when it comes to your exact diagnosis. Let’s look at an example. This was a patient who was referred to me by her general dentist, who said she had pain when she saw him. But by the time she saw me, the pain was gone!

Was she magically cured? Were all of her teeth’s nerves dead? We can’t make assumptions; we have to properly diagnose. I wasn’t getting any solid clues from her x-rays, so I decided to take a CBCT image.

I had to go through all the slices one by one. Everything was looking great until I got deep enough into the tooth, and I noticed a tiny radiolucency around the roots and a thickened sinus membrane (marked with yellow and green arrows). That told me that tooth #3 was necrotic.

The patient’s story about having pain that then went away is often a sign that a nerve has died. Through my cone beam, I got to the root of the issue (pun intended!).

Cone Beams Help Determine Why a Root Canal Actually Failed

When your provider knows why your root canal failed, they can retreat it and prevent another future failure. Let me show you an example! Here’s a patient who had a failed root canal (the one on the left, tooth #19). You’ll see a dark J-shaped shadow hugging the root; that’s called a J-shaped radiolucency.

At first glance, it seems like the tooth might be fractured. But look at the next image from the CBCT. See where the yellow arrow is pointing? That’s a missed canal! It’s still dark, while the other canals are white. That black canal still has bacteria from the old original infection in it. Good news, that means this tooth is saveable with a new, thorough root canal!

Going back to standard x-rays, look at the before and after here. See how there’s a whole new canal that’s lit up in white on the second image compared to the first? That’s that missed canal, post retreatment.

The retreatment worked, too. Check out this two-year post-treatment x-ray. The bone is regrowing, and that J-shaped radiolucency is gone. Hooray!

Here’s another way that cone beam CT works: it helps your dentist make an accurate diagnosis, so they recommend the appropriate treatment for your tooth.

Cone Beam CT Helps Your Dentist Save Your Teeth

My mission on this earth is to save more teeth. Nothing feels or fits better than your natural teeth your mama gave you! Plus, your natural teeth make a difference with your digestion, airway, speech, confidence, and smile. I recommend you find a dentist or endodontist who not only has CBCT in their office, but who also knows how to use it. In fact, you may want to ask your provider directly about how comfortable they are with CBCT technology. It has a learning curve, so it can take some time for dentists to know all of its ins and outs.

– Sonia