X-Rays in Dentistry: Safety and Common Uses

Why dental X-rays are a vital diagnostic tool

Dental X-rays, also called radiographs, allow your dentist to see what is happening beneath the surface of your teeth and gums – areas that are invisible during a visual examination. Without them, problems such as decay between teeth, infection at the root tip, bone loss from gum disease and impacted wisdom teeth can go undetected until they cause pain or serious damage. Catching these issues early often means simpler, cheaper and less invasive treatment. A small cavity found on an X-ray might need a straightforward filling, while the same decay left unnoticed could lead to a root canal or extraction.

Are dental X-rays safe?

Yes – when used appropriately, dental X-rays are very safe. The amount of radiation involved is extremely low. Modern digital X-rays use up to 80% less radiation than traditional film, and a full set of bitewing X-rays exposes you to roughly the same amount of background radiation you would receive from a short aeroplane flight or a few hours of natural sunlight. Your dentist follows the principle of ALARA – “As Low As Reasonably Achievable” – which means they only take X-rays when there is a clear clinical reason and use the lowest dose possible.

Safety measures are standard in UK dental practices. You will usually wear a lead apron and sometimes a thyroid collar. The X-ray machine itself is checked regularly, and staff stand behind a protective screen. If you are pregnant or think you might be, always tell your dentist. Routine X-rays are often postponed until after birth, but if you have a dental emergency, a single X-ray with shielding is generally considered safe. Your dentist will discuss the risks and benefits with you.

Common types of dental X-ray

Different X-rays show different things. Your dentist will choose the right one for your needs.

• Bitewing X-rays: The most common type. You bite on a small tab while the X-ray captures the crowns of your back teeth. They reveal decay between teeth and check the height of bone supporting your teeth. Usually two to four bitewings are taken at a time.
• Periapical X-rays: These show the whole tooth from crown to root tip, plus surrounding bone. They are used to check for abscesses, cysts, root fractures or to plan root canal treatment.
• Panoramic X-rays (OPG): A single image of your entire mouth, including jaw joints and sinuses. They help assess wisdom teeth, orthodontic treatment, implants and jaw problems.
• Occlusal X-rays: Less common in adults, these show the floor of the mouth and are sometimes used in children to check developing or extra teeth.
• Cone beam CT (CBCT): A 3D scan giving detailed images of bone and tooth structure. It is used for complex implant planning, tricky root canals or surgical procedures.

How often do you need dental X-rays?

There is no fixed schedule that suits everyone. Your dentist will recommend X-rays based on your individual risk of dental disease, your age, your medical history and any symptoms. As a general guide:

• Adults with good oral health: Bitewing X-rays every 12 to 24 months, and a panoramic X-ray every three to five years if there is a clinical reason.
• Adults at higher risk: If you have a history of frequent decay, gum disease, dry mouth or a weakened immune system, your dentist may suggest X-rays every six to 12 months.
• Children and teenagers: X-rays are more frequent because their teeth and jaws are still developing. A first X-ray is often taken around age five or six to check for decay between back teeth and to monitor how adult teeth are coming through. After that, bitewings may be taken every six to 18 months, depending on risk.

UK dental guidelines emphasise that X-rays should be justified for each patient – never taken as a routine “just in case”. If you are unsure why an X-ray is needed, it is always fine to ask.

X-rays and preventive care for children

Children can develop tooth decay surprisingly quickly, and it often starts between teeth where you cannot see it. X-rays allow your dentist to catch early decay before it becomes a cavity, which means treatment can be simpler – sometimes just a fluoride varnish or a small sealant. X-rays also help track the development of adult teeth, spot missing or extra teeth, and identify problems with jaw growth that might need orthodontic attention.

The procedure is quick and painless. Your child will bite on a small plastic holder while the X-ray machine takes a picture. It takes a few seconds. Children may find the lead apron a bit heavy, but it is nothing to worry about. You can stay with your child for reassurance. If your child is anxious, tell the dental team – they are used to helping nervous young patients.

What to expect and questions to ask

Having a dental X-ray is straightforward. You will sit in the chair, the dental nurse will position the X-ray film or sensor inside your mouth, and you will need to stay very still for a moment. The machine may whirr briefly. You will not feel anything. The images appear on a screen almost instantly with digital X-rays, so your dentist can discuss the findings with you right away.

It is your right to understand why an X-ray is being taken. Good questions to ask include: Why do I need this X-ray? How often will I need them? Are you using digital X-rays? What will you do with the results? If you change dental practice, you can request that your previous X-rays are forwarded – this avoids unnecessary repeat imaging. Used wisely, X-rays are a tool for prevention, not a replacement for daily brushing, flossing and regular check-ups. They help keep your smile healthy for life.