Dental X-Rays: How Much Radiation and How Often
Quick answer: dental x-rays use very little radiation. A standard dental x-ray is about 0.005 mSv, roughly the same as one day of natural background radiation, and a panoramic x-ray is about 0.025 mSv, about three days. How often you need them depends on your risk of tooth decay: adults with no cavities and low risk may only need bitewing x-rays every 24 to 36 months, while people with active decay may need them every 6 to 18 months. Since 2024, the American Dental Association no longer recommends lead aprons or thyroid collars, including during pregnancy.
As someone who works with radiation every day, I get asked about dental x-rays more often than you might think, usually by worried parents. The short version: the doses are tiny, and the real question is whether each x-ray is needed.
How much radiation is in a dental x-ray?
These are approximate effective doses for an average-sized adult, from the American College of Radiology and RSNA. For comparison, the average person in the U.S. receives about 3 mSv per year from natural background radiation.
| Exam | Approximate dose | Same as natural background for about |
|---|---|---|
| Dental x-ray | 0.005 mSv | 1 day |
| Panoramic x-ray | 0.025 mSv | 3 days |
| Chest x-ray (for comparison) | 0.1 mSv | 10 days |
| Dental cone beam CT (CBCT) | 0.18 mSv | 22 days |
| Chest CT (for comparison) | 6.1 mSv | 2 years |
A coast-to-coast round-trip flight is about 0.03 mSv, more than a panoramic x-ray. Actual doses vary with the equipment, the number of images and the patient’s size.
The main types of dental x-rays
- Bitewings: small images of the back teeth, used mainly to find decay between teeth. These are the most common routine x-rays.
- Periapical: images of one or a few whole teeth, from crown to root, used to look at roots and the surrounding bone.
- Panoramic: a single wide image of all the teeth and jaws, taken by a machine that rotates around your head.
- Full-mouth series: a set of bitewing and periapical images covering the whole mouth.
- Cone beam CT (CBCT): a 3D scan used for specific needs such as implants, impacted teeth or complex root problems. It uses more radiation than standard dental x-rays, so the ADA recommends it only when lower-exposure options cannot give the information needed.
How often do you need dental x-rays?
The American Dental Association and the FDA publish recommendations based on age and risk of decay. For people coming back for regular checkups (recall patients), the suggested intervals for bitewing x-rays are:
| Patient | Active decay or higher risk | No decay and low risk |
|---|---|---|
| Children | Every 6 to 12 months (if the back teeth touch) | Every 12 to 24 months (if the back teeth touch) |
| Adolescents | Every 6 to 12 months | Every 18 to 36 months |
| Adults | Every 6 to 18 months | Every 24 to 36 months |
For new patients, the dentist decides on an individualized set of images. A full-mouth series is preferred when there is widespread disease or a history of extensive dental work. For gum disease, the guidelines leave the timing to the dentist’s judgment.
These are recommendations, not fixed rules: your dentist adjusts them to your history. If you are told you need x-rays every year despite no cavities and low risk, it is reasonable to ask why.
Are lead aprons and thyroid collars still needed?
No longer recommended. In 2024, an expert panel of the American Dental Association concluded that lead aprons and thyroid collars are not necessary to shield patients during dental x-rays. Modern digital equipment narrows the beam to the area being imaged, which protects the rest of the body. Shields can even block the beam and force a retake, which means more radiation, not less. The recommendation applies to all patients, regardless of age or pregnancy.
Some states still have laws requiring shields, and changes take time, so your dentist may still offer one.
From the scanner room: [TU EXPERIENCIA: en medicina también se ha reducido el uso de protectores de plomo; explica en 2-3 frases cómo vives tú este cambio y por qué los pacientes siguen pidiéndolos.]
More on this in [link: Lead Aprons: Why Many Hospitals Stopped Using Them].
Dental x-rays during pregnancy
Dental x-rays deliver a very small dose, and the beam is aimed at the mouth, far from the abdomen. The ADA’s 2024 recommendations on shielding explicitly include pregnant patients. Still, tell your dentist if you are pregnant so they can decide which images are truly needed, and do not delay necessary dental care. See [link: CT Scans During Pregnancy: What Patients Should Know] for imaging in pregnancy more generally.
Dental x-rays and children
Children are more sensitive to radiation than adults, which is why the guidelines tie x-ray frequency to each child’s risk of decay and why dentists use the smallest number of images needed. Digital x-rays and narrow beams keep doses very low. See [link: Medical Radiation and Children: What Parents Should Know].
How to keep your exposure low
- Share previous x-rays when you change dentists, so they are not repeated unnecessarily. The ADA encourages using images from previous exams whenever possible.
- Ask why an x-ray is needed if it seems frequent for your situation.
- Keep your teeth healthy: lower decay risk means longer intervals between x-rays.
Tips from the technologist
[TU EXPERIENCIA: 2-3 consejos propios. Ideas: quedarse muy quieto para no repetir la imagen, avisar de náuseas con las placas intraorales, pedir copia de las imágenes.]
Frequently asked questions
Are dental x-rays safe?
Yes. They use some of the lowest radiation doses of any x-ray exam, comparable to about one day of natural background radiation for a standard dental x-ray.
How many dental x-rays are too many?
There is no fixed number. The guidelines aim to take x-rays only when they add useful information, at intervals based on your risk.
Is a panoramic x-ray more radiation than bitewings?
A panoramic x-ray is about 0.025 mSv, compared with about 0.005 mSv for a dental x-ray, but both are very low.
Is a dental cone beam CT safe?
It uses more radiation than standard dental x-rays (about 0.18 mSv) but far less than a medical CT. It is used only when needed.
Can I refuse dental x-rays?
You can discuss it with your dentist. Without x-rays, some problems, such as decay between teeth or infections at the roots, can be missed.
This article is for general information and does not replace advice from your dentist.
Sources
- RadiologyInfo.org (ACR and RSNA): Radiation Dose
- American Dental Association: updated recommendations on radiography safety (2024)
- U.S. FDA: The Selection of Patients for Dental Radiographic Examinations
- Dentalcare.com: ADA/FDA selection criteria table
- WebMD: Lead aprons no longer needed during dental x-rays