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Dental X-rays are pictures that show what a dentist cannot see by looking in your mouth. Here is why a dentist might take them, what the visit is like, and what grown-ups can ask.
A dental X-ray is a quick picture of the inside of your teeth and the bones around them. The dentist looks with a mirror, but a mirror cannot see between your teeth or beneath the surface. An X-ray can.
Your goal today: learn what an X-ray picture can show, and how you can help the dentist take a good one.
Your job is to hold still for a moment, like a statue. If anything feels strange, tell the team. They are happy to explain.
The X-ray shows the parts the mirror cannot reach. It can show a cavity hiding between teeth, or where grown-up teeth are getting ready to come in.
Taking X-rays is a short, quiet job. Here is what usually happens:
Dentists do not take X-rays just because it is time for a visit. They take them when a picture will help answer a question. An X-ray has three main jobs.
Dentists use X-rays to find and keep an eye on problems, such as a cavity hiding between two teeth.
After a bump or a fall, an X-ray can show what happened to a tooth and the bone around it.
X-rays show how teeth and jaws are growing, and how a treatment is going.
It can show the inside of teeth and the bones around them. That includes a cavity hiding between teeth, and where grown-up teeth are getting ready to come in.
Tell the team. They can show you the sensor first, and you can ask to see the picture afterward.
Every child is different, so there is no single schedule. The AAPD says the timing of the first X-rays, and how often to repeat them, depend on each child: medical and dental history, what the dentist finds, and the child’s risk of cavities. Age or insurance coverage are not, on their own, reasons to take X-rays.
As general guidance from the ADA and FDA, reprinted by the AAPD, the usual picture for checking the spaces between back teeth is a bitewing. Dentists consider bitewings only if those spaces cannot be checked by looking or with a probe. For a child with no cavities and no higher risk, that is about every 12 to 24 months with baby teeth only, and about every 18 to 36 months once the first permanent tooth has come in. For a child with cavities or higher risk, it is about every 6 to 12 months. These are guidelines, and the dentist’s judgment comes first.
No. The AAPD says X-rays are not screening tools. A new patient with only baby teeth, no signs of disease and open spaces between the teeth may not need an X-ray at that visit. Ask your dentist why an X-ray is recommended now and how the result will change the plan.
The AAPD says X-rays are meant to diagnose or monitor disease, check injuries to teeth, follow how teeth and jaws are developing, and see how treatment is going. Dentists often consider them when there is a history of pain or injury, swelling, loose teeth, deep cavities, or teeth that are coming in or moving in an unusual way.
The radiation from dental X-rays is low, but the effects of radiation add up over time. So the AAPD asks dentists to weigh the benefit of each X-ray against its risk and to follow the ALARA principle, which means as low as reasonably achievable. Pictures taken inside the mouth (intraoral) are the standard tool for children.
Examples in AAPD guidance include using the fastest image receptor that still gives a clear picture (a digital sensor or fast film), narrowing the beam to the size of the receptor, using correct settings, and taking only the images that are needed. You can ask your office how they protect your child.
Guidance has changed. The AAPD no longer recommends routine shielding with lead aprons or thyroid collars, in line with the American Academy of Oral and Maxillofacial Radiology. Better technology, such as narrowed beams and digital sensors, has greatly lowered exposure. A shield does not block scatter radiation inside the body, and a shield that is in the way can spoil the picture, so the X-ray has to be taken again, which adds radiation.
Some states, such as California, still require shielding by law, so your child’s dental office may still use one. If you have questions, ask the dentist.
Sometimes a good picture cannot be taken, for example because a child cannot cooperate. The AAPD says the dentist usually explains this and the options to the parent. Whether to treat without the X-ray depends on how urgent the problem is, whether another setting is available, and the risks and benefits of each choice.
Often a dentist can review earlier X-rays, from the same office or sent from a previous one, before deciding whether new ones are needed. If your child has had recent X-rays elsewhere, ask the old office to send them.
Bitewings show the crowns of the back teeth and the spaces between them. Periapical pictures show a whole tooth, from the crown to the root tip and the bone around it. A panoramic picture shows all the teeth and jaws in one image. Occlusal views show a wider area of the biting surface. A 3D scan called cone beam CT is not used for a first diagnosis without a reason. The AAPD says it can help when regular X-rays are not enough and the benefit outweighs the added radiation.
The clinical statements on this page come from the American Academy of Pediatric Dentistry (AAPD) best practice on prescribing dental radiographs, which endorses the ADA and FDA recommendations. The plain descriptions of X-ray types are general descriptions to be confirmed in clinical review.
Review status: pending. No named reviewer or review date yet.
This website is for education only and does not replace care from your dentist, physician, or emergency services.