Dental X-rays — what they are, why we need them, and why they are safe

X-rays are one of the most valuable diagnostic tools in dentistry — but we completely understand that some patients have questions or concerns about them. Here's everything you need to know.

What are dental X-rays?

Dental X-rays are images that allow your dentist to see parts of your teeth, gums, and jaw that are simply not visible to the naked eye. Think of them as a window beneath the surface — revealing what's happening inside and between your teeth, under the gumline, and within the jawbone itself.

There are several types of dental X-rays, each serving a different purpose:

Bitewing X-rays

• Show the upper and lower back teeth biting together in a single image

• Used to detect cavities between teeth and assess bone levels

• One of the most routinely taken X-rays in general dentistry

Periapical X-rays

• Show the entire tooth from crown to root tip, including the surrounding bone

• Used to assess the root, detect infections or abscesses at the root tip, and evaluate bone levels around individual teeth

• Commonly taken when a specific tooth is causing concern

Panoramic X-ray (OPG — Orthopantomogram)

• A single wide image showing all your teeth, both jaws, the sinuses, and surrounding structures in one view

• Gives your dentist a broad overview of your entire oral and facial structures

• Commonly taken as part of an orthodontic records appointment, when planning implants, or when assessing wisdom teeth

• Does not show fine detail as well as individual periapical X-rays — but provides invaluable big-picture information

Cephalometric X-ray (Ceph)

• A standardised side-profile X-ray of the skull

• Used primarily in orthodontics to assess the relationship between the jaws and teeth, evaluate growth patterns, and plan treatment

• Allows your dentist to take precise measurements of your jaw and facial structures to guide treatment decisions

Cone Beam Computed Tomography (CBCT)

• A three-dimensional X-ray that produces a highly detailed 3D image of the teeth, jaws, bone, and surrounding structures

• Unlike conventional X-rays which produce flat 2D images, CBCT allows your dentist or specialist to view structures from every angle — length, width, and depth

• Think of it as the difference between a photograph and a sculpture — conventional X-rays give you the photograph, CBCT gives you the full three-dimensional picture

Why is CBCT needed?

CBCT is not a routine X-ray — it is taken when a higher level of detail and three-dimensional information is required that cannot be obtained from conventional X-rays alone. Your dentist or specialist may recommend a CBCT for:

• Implant planning — to assess the exact volume, density, and shape of available bone, and to identify the precise location of nerves and sinuses before implant placement

• Orthodontic assessment — particularly for impacted teeth, unusual tooth positions, or complex jaw relationships that require 3D visualisation

• Impacted wisdom teeth — to assess the relationship of wisdom tooth roots to the inferior alveolar nerve before surgical removal

• Airway assessment — to evaluate the upper airway in patients with breathing concerns or sleep apnoea

• TMJ assessment — to evaluate the temporomandibular joint in detail

• Root canal treatment — to assess complex root canal anatomy, detect missed canals, or evaluate the outcome of previous treatment

• Trauma and fractures — to assess the extent of jaw fractures or root fractures in detail

• Cysts, tumours, and pathology — to determine the size, extent, and relationship to surrounding structures

Is CBCT safe?

CBCT does deliver a higher radiation dose than conventional dental X-rays — but it is still considered low compared to many medical CT scans. It is always recommended only when the clinical benefit of the additional information it provides outweighs the risk of the higher dose. Your dentist or specialist will only recommend a CBCT when it is genuinely necessary and when the information cannot be obtained from conventional X-rays alone.

Why are X-rays needed?

There is a great deal that your dentist simply cannot see without X-rays — no matter how thorough the clinical examination. X-rays allow your dentist to:

• Detect cavities between teeth that are invisible to the eye and not yet causing symptoms

• Assess the health of the bone supporting your teeth

• Detect infections, cysts, or abscesses at the root tips

• Monitor the development and position of teeth — especially important in children and orthodontic patients

• Assess wisdom teeth and their proximity to nerves before removal

• Plan implants, extractions, and other procedures with precision

• Detect root fractures or other hidden damage

• Obtain three-dimensional information about bone, nerves, and structures when conventional X-rays are insufficient

Catching problems early — before they cause symptoms — almost always means simpler, less invasive, and less costly treatment. X-rays make this possible.

Are dental X-rays safe?

This is one of the most common questions we receive — and the reassuring answer is yes, dental X-rays are very safe.

Here's some perspective:

• The radiation dose from a routine dental X-ray is extremely low — a full set of bitewing X-rays exposes you to roughly the same amount of radiation as a short aeroplane flight, or a day of natural background radiation from the environment

• Modern digital X-ray systems use significantly less radiation than traditional film X-rays

• CBCT delivers a higher dose than conventional dental X-rays but remains low compared to medical CT scans — and is only recommended when clinically justified

• X-rays are only taken when there is a clear clinical reason to do so — your dentist will never take them unnecessarily

• The risk of not taking X-rays — missing a cavity, an infection, or a developing problem — often far outweighs the minimal risk of the X-ray itself

What about X-rays during pregnancy? If you are pregnant or think you may be pregnant, always inform your dentist before any X-rays are taken. While the radiation dose from routine dental X-rays is very low, they are generally deferred during pregnancy unless there is an urgent clinical need. CBCT is avoided during pregnancy.

What about X-rays for children? Children may actually benefit more from X-rays than adults in some cases — as they allow monitoring of developing teeth and early detection of problems. The frequency and type of X-rays taken will always be carefully tailored to the child's individual needs and risk level, using the lowest dose necessary.

💡 Dr Watt's tip: I completely understand the instinct to want to minimise any kind of radiation exposure — it's a completely reasonable concern. But the dose from a routine dental X-ray is genuinely tiny, and the diagnostic value they provide is enormous. Skipping X-rays to avoid radiation often means missing problems until they become much bigger — and much more treatment-intensive — than they needed to be. Every X-ray I take is taken for a reason, and I will always explain why. 😊