Radiographs show three things that cannot be seen by looking into a mouth: decay between teeth where they touch, the level of bone supporting the teeth, and what is happening at the root tips and inside the jaw. All three can be well advanced while the mouth looks entirely healthy.
They are taken when there is a clinical reason, not at every visit, and the interval should be based on your individual risk.
What they show
Decay between teeth
Where two teeth touch, neither eye nor instrument can reach the contact point. This is one of the most common places for decay to start, and it is invisible until it has progressed far enough to undermine the surface. A bitewing radiograph shows it early, while a small filling would still do.
Bone levels
Gum disease destroys the bone supporting the teeth. Probing measures the pockets; radiographs show the bone itself and allow comparison over years. This is the objective record of whether periodontal disease is stable or progressing — see periodontitis: when bone is involved.
Infection at the root tip
A dark area at the end of a root indicates infection spreading from inside the tooth into the bone. It is frequently painless.
Decay beneath existing fillings and crowns
Not visible from the outside.
Unerupted, impacted and developing teeth
Wisdom teeth, whether a child’s permanent teeth are all present and heading in the right direction, and teeth that have failed to erupt.
Cysts and other pathology in the jaw
Uncommon, usually painless, and found incidentally — which is one of the better arguments for periodic imaging.
Bone volume for implant planning
Height, width and the position of the sinus and the nerve canal. This is measured, not estimated — see who is a candidate for dental implants.
The types
Bitewings — small films showing the crowns of the upper and lower back teeth together. The standard for detecting decay between teeth and checking bone levels.
Periapical — shows one or two teeth in full, including the roots and the bone around the tips. Used for diagnosing a painful tooth, before and during root canal treatment.
Panoramic (OPG) — a single image of both jaws, all the teeth, the joints and the sinuses. Lower detail, wide coverage. Used for wisdom teeth, development in children, and an overview.
CBCT — a three-dimensional scan. Higher dose than the others and used where the third dimension genuinely matters: implant planning, difficult wisdom teeth near the nerve, complex root canal anatomy, and assessing pathology.
The safety question, answered straight
Dental radiographs use a very small dose of ionising radiation. Modern digital sensors require considerably less than the film they replaced, and beams are collimated to the area being examined. Protective measures are used as appropriate, and equipment is subject to regulation and regular testing.
The principle that governs their use is that every exposure must be justified by a clinical benefit, and kept as low as reasonably achievable. That is why a dentist will decline to take a radiograph “just to check” when there is no clinical indication — and it is also why they will insist on one before implant surgery or when diagnosing a painful tooth.
If you are worried, the reasonable questions are: what is this one for, what would change depending on the result, and is there another way to get that information. A clear answer to those is more useful than a dose figure.
Pregnancy
Tell us if you are pregnant or think you may be. Routine radiographs are generally deferred. Where there is an urgent diagnostic need — a painful tooth or an infection — imaging can be taken with appropriate precautions, because an untreated dental infection carries its own risks.
Children
Not routine. Taken when there is a reason, such as suspected decay between teeth or a concern about development. See what happens at a child’s check-up.
How often
There is no universal interval. Someone with active decay, a history of gum disease, many restorations, or a dry mouth needs imaging more frequently than someone with healthy gums and no decay for years. Your dentist should be able to tell you why your interval is what it is.
Ask to see them
This is worth doing. Radiographs are displayed on a screen and a dentist can show you exactly what they are describing — the shadow between two teeth, the bone level compared with five years ago, the dark area at a root tip. It turns an opinion into something you can see, and it makes the treatment decision yours rather than something you are told.
You are also entitled to copies of your own radiographs, which is particularly worth having if you move, travel for treatment, or want a second opinion.
Frequently asked questions
Can I refuse?
Yes. Bear in mind that a dentist may be unable to diagnose or to proceed safely without them — implant surgery without imaging, for instance, is not something any responsible clinician will do.
Do I need new ones if I have recent ones from another dentist?
Often not. Ask your previous dentist for copies and bring them.
Why a CBCT scan rather than an ordinary radiograph?
Because some questions cannot be answered in two dimensions — how close a root is to a nerve, how much bone width exists. It should be justified, not routine.
Are they taken at every check-up?
No. At intervals appropriate to your risk.
Ask what the image is for
A radiograph should always have a purpose you can be told. See our dental X-rays page and what a dental check-up includes.
To arrange a consultation at our clinic on Abbas El-Akkad in Nasr City, call +20 101 969 7597 or message us on WhatsApp.
