Dental X-Rays: Why We Take Them and How Often You Need Them

Patients ask me about x-rays more than almost anything else during a routine visit. Usually it comes out as some version of: do I really need these, and how often? That's a fair question, and the honest answer is not "every time you come in."

Here is how I think about it, and what you can reasonably expect in our office.

What an Exam Alone Can't Show

When I look in your mouth, I can see the chewing surfaces of your teeth, your gums, your tongue, and the surfaces facing your cheeks and tongue. That is a lot of useful information. But a few things are genuinely hidden from view:

• Decay starting between two teeth that are touching each other

• Decay underneath an existing filling or crown

• Bone loss from gum disease, which happens below the gumline

• Infection at the root tip of a tooth

• Teeth that haven't come in yet, including wisdom teeth, and which direction they're pointing

• Cysts and other changes inside the jawbone

None of those show up reliably on a visual exam. By the time a cavity between two back teeth is visible to the eye or starts to hurt, it is usually much bigger than it needed to be. That is the main reason we take radiographs: to catch small problems while they are still small and simple to fix.

The Types You'll Run Into

• Bitewings. Small images showing the crowns of the back teeth, upper and lower together. These are the workhorses for finding decay between teeth and checking bone levels.

• Periapical. Shows one or two teeth from the crown all the way down to the root tip. This is what I take when a specific tooth is bothering you, or before and after a root canal.

• Panoramic. One wide image of both jaws, the sinuses, and the jaw joints. Useful for wisdom teeth, implant planning, and a broad look at anything unusual.

• Cone beam CT. A three-dimensional scan, used selectively, most often for implant planning or a complicated extraction. This is not a routine image.

How Often Is Right

There is no single schedule that fits everyone, and that isn't me dodging the question. It is the actual guidance: the American Dental Association and the FDA both recommend that dental x-rays be prescribed based on the individual patient and their exam, rather than taken automatically at fixed intervals.

In practice, that tends to look like this:

• If you've had little decay, solid home care, and stable gums, bitewings every couple of years may be plenty.

• If you get cavities easily, have gum disease, a dry mouth, many existing fillings, or a history of root canals, more frequent images make sense.

• Children and teenagers often need them somewhat more often, since their teeth are still developing and decay tends to move faster through young enamel.

• A new patient usually needs a baseline set, simply because I have nothing yet to compare against.

If anyone tells you that you need a full set at every single visit regardless of your history, it is reasonable to ask why.

What About the Radiation?

The dose from a dental x-ray is very low, and it is lower than it was a generation ago, because digital sensors need considerably less exposure than film did. You also absorb background radiation every day just from living on this planet, and a few dental images are a small addition to that.

Low is not zero, though, and I don't treat it as zero. That is the entire reason for not taking images we don't need, for using a lead apron and thyroid collar where appropriate, and for keeping the field as small as the question allows. If you've had x-rays taken recently somewhere else, tell us. Most offices will forward them, and that is one less set to take.

If You're Pregnant

Routine x-rays can usually wait until after delivery. But if you have a toothache, swelling, or a suspected infection, the better move is almost always to diagnose it and treat it. An untreated dental infection carries real risk during pregnancy, and dental radiography with proper shielding is considered safe when it is genuinely needed. Tell us if you're pregnant or think you might be, and we'll make that decision together.

You Can Ask, and You Can Decline

You are allowed to ask what a particular image is for and what I'm looking for in it. You are also allowed to say no. If you decline, I'll tell you plainly what I can and cannot diagnose without it, so you know exactly what you're accepting. Some things I simply cannot rule out by looking.

And if we do take them, ask to see them. I would much rather turn the screen toward you and show you the dark spot between two molars than just tell you it's there.

The Short Version

X-rays are a diagnostic tool, not a formality. Used thoughtfully, they let us find trouble early, when treatment is smaller, cheaper, and easier on you. Used reflexively, they're just extra exposure. The goal is to take the images that answer a real question, and skip the ones that don't.

This post is general information and not a diagnosis. What's right for your teeth depends on your own history, your exam, and your risk for decay and gum disease. If you're due for a checkup, or a tooth has been bothering you, we're glad to take a look.

Hashimi Dental, 3701 Market St. Suite E, Riverside, CA 92501