Dental CT Scans, Explained
Why planning an implant calls for a three-dimensional view, when a scan is justified and when it isn't, what the dose really means, and how the image turns into a printed surgical guide.
What Can a Dental CT Scan Show Me, and Is the Radiation Safe?
A dental CT scan, often called a CBCT or cone beam CT, is a 3D X-ray of the jaws. It shows how wide and how tall the bone is, the route of the nerve inside the lower jaw, where the sinuses sit and how the roots lie, which is detail no flat X-ray can give. The dose sits above a small dental X-ray but well below a hospital body scan, and much nearer the former, and we only recommend one when the result would alter your treatment. At our Broughty Ferry practice a scan on our own machine costs £160, and for full-arch treatment it is built into the fee.
A Flat X-Ray Against a 3D Scan
An ordinary dental X-ray is best thought of as a snapshot from one viewpoint only. It gives a fair idea of bone height and the shape of the roots, but every structure is flattened onto one plane. What it cannot show is the width of bone between the cheek side and the tongue side, or the exact depth of the nerve.
A cone beam CT scan captures an entire block of jaw in three dimensions. We can turn the image on screen, cut through it at any angle we choose, and measure distances to within a fraction of a millimetre. When it comes to implants, that replaces estimation with proper planning.
What Appears on the Scan
- Width and height of bone at the gap, from which we know whether an implant will fit and which size to choose
- Bone density, a rough measure of how firm the bone is
- The inferior alveolar nerve, the canal within the lower jaw that supplies feeling to the lower lip
- The floor of the sinus above the upper back teeth, which frequently sits close to the ridge
- Adjacent roots, so an implant can be kept a safe distance from them
- Unsuspected findings like long-standing infection, a cyst, or a fragment of root that was left behind
Considering Dental Implants?
Arrange a free implant consultation at our Broughty Ferry practice. Where a scan is called for, we can usually take it there and then.
When a Scan Is Justified
| Situation | Why a scan helps |
|---|---|
| One implant or several | So the size, position and angle of each implant can be chosen safely |
| A bone graft may be needed | To judge if there's enough bone, and if not, how much rebuilding is needed |
| Implant-retained dentures | To find the best sites for the implants the denture will clip to |
| Full-arch treatment | To plan tilted implants that steer clear of the sinus and the nerve, frequently with no graft |
| A troublesome existing implant | To measure how much bone still surrounds it |
Routine examinations are a different matter: small digital X-rays show everything needed at a fraction of the dose. A CT scan always has to be justified, so we take one only when the three-dimensional picture will change the treatment. Where you don't need one, we will say so.
Understanding the Radiation
Every X-ray uses a small quantity of ionising radiation, so the principle is always the lowest dose that still answers the clinical question. Set against one small film, a cone beam scan delivers more, because it images a larger volume, yet far less than a hospital medical CT, which takes in more of the body. Restricting the scanned field to the section of jaw we actually need, and using the lowest settings that still produce a sharp image, keeps the dose down.
UK regulations oblige a clinician to justify every exposure, which is why a scan cannot simply be ordered on request. If there is any chance you are pregnant, please say so: there's nearly always no harm in postponing implant planning, and that is normally what we would do.
What the Scan Feels Like
The whole thing is over quickly, and the only contact is a chin rest and a small block to bite on. Glasses, earrings, hair clips, necklaces and any denture you can take out all come off first, since metal around the head distorts the image. You then sit or stand still for a few seconds as the arm of the machine travels once around your head. There is no tunnel to lie in, and nothing is injected.
The images are up on screen inside a minute or two. Our implant dentist will go through them with you at the consultation, pointing out the ridge, the path of the nerve and where an implant would go. A copy is yours if you want one.
How the Scan Becomes Surgery
Treatment planning starts with the scan. Working on the 3D model, our implant dentist positions a virtual implant, tuning its depth, angle, width and length to match your bone while keeping a safe distance from the nerve and sinus. The future crown is planned at the same time, so that the implant lines up properly with the tooth it will carry.
From that plan a surgical guide is printed. On the day of surgery it sits in your mouth and directs each MegaGen AnyRidge implant into its planned position using MegaGen's R2 guided system. With the position fixed in advance, the opening made in the gum can often be smaller. Among the four full-arch pathways, only Premium Guided Zirconia includes a custom guide of this kind, and on the two same-day pathways the plan also lets the fixed temporary teeth be made ready before surgery. If another practice has ruled out implants for you based on nothing more than a flat X-ray, a scan gives a sound basis for a second opinion.
What It Costs
| Scan | Fee |
|---|---|
| CT scan | £160 (plan members pay £144) |
| CT scan when referred by a dentist elsewhere | £160 |
| Full-arch treatment, each arch, scan included | From £9,300 |
| Small X-ray (plan members pay nothing) | £10 |
There is no charge for the implant consultation; a booking deposit of £40 comes back to you within 7 days of attending. A scan is only charged for if one is needed. For full-arch work there are four pathways, each with one fee per arch from £9,300 to £14,950, and every one of them includes the CBCT scan, 3D planning, the implants and the permanent bridge. 1 Extractions, temporary teeth and a surgical guide are included only on the pathways that involve them. The remaining fees are set out in our implant cost guide.
Sending a Patient to Us for a Scan
Dentists and other registered clinicians, whether in Broughty Ferry, elsewhere in Dundee and Angus, or further afield, can refer patients to our practice for a cone beam scan (£160) or for an iTero Lumina intraoral scan (£120). 1 The scan goes back to you securely as DICOM files inside 48 hours, ready to load into your planning software. What we provide is the imaging itself rather than a written radiology report.
A patient cannot self-refer for an X-ray, though anyone is welcome to arrange a free consultation, and where a scan is justified we can take it at that appointment. The referral form is on our referrals page, and our other equipment is described on the technology page.
Questions
This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.