CBCT or OPG: which one does your clinic actually need?
A panoramic unit answers most everyday questions. A CBCT answers the ones that decide an implant, a difficult endo or a surgical extraction. Here is how to tell which your clinic needs first.
Almost every clinic that calls us about 3D imaging opens with the same sentence: "we are thinking about a CBCT, but we already have an OPG." The two machines overlap far less than the brochures suggest, and the decision usually comes down to which questions you are tired of answering with a guess.
What a panoramic image gives you
An OPG is a survey. In one exposure you see both arches, the sinuses, the condyles and the general state of the bone. For screening, for a first appointment, for orthodontic assessment and for tracking a lesion over time, it is quick, low-dose and entirely sufficient.
What it cannot do is separate structures that sit behind one another. A panoramic image is a curved slice flattened onto a single plane, so it collapses depth. Everything you would actually like to know before placing an implant — how wide the ridge is, where the canal runs, how close the sinus floor sits — lives in the dimension the image has thrown away.
What CBCT adds
A cone beam scan reconstructs the same anatomy as a volume, so you can move through it slice by slice and measure in millimetres.
Where 3D changes the decision, not just the picture
- Implant planning. Ridge width, bone density and the exact position of the inferior alveolar canal, before the flap rather than during it.
- Endodontics. A second mesiobuccal canal, a missed isthmus, a vertical root fracture — findings a 2D image routinely hides.
- Impacted teeth. Whether that third molar is truly on the canal, and which way it is displaced.
- Pathology and surgery. The true extent of a lesion, and its relationship to what you are about to cut.
Radiation, honestly
A CBCT is a higher dose than a panoramic image; anyone who tells you otherwise is selling something. The useful comparison is not CBCT against OPG, it is a small field-of-view CBCT against the alternative you would otherwise reach for — often a medical CT at many times the dose, or a surgical decision made on incomplete information.
Field of view is the control that matters. Scanning a single quadrant at the smallest field that answers the question keeps the dose close to a couple of panoramic exposures. Scanning the whole head because the machine can is how a practice ends up justifying itself to a regulator.
So which should you buy first?
An OPG is the right first machine when
- most of your imaging is screening, recall and orthodontic assessment;
- you refer implant and surgical cases out;
- you are replacing film or an ageing analogue unit and want the workflow win first.
Go straight to 3D when
- you place implants yourself, even occasionally — one avoided complication pays for a great deal of imaging;
- you do surgical extractions or endodontic retreatment in-house;
- you are already sending patients out for scans and paying for the privilege in time, goodwill and lost follow-up.
The middle path most clinics actually take
You do not have to choose. A combined unit gives you panoramic imaging as the daily workhorse and a cone beam volume on the days that need one, from one footprint and one sensor. That is the logic behind machines like Green X and the VATECH A9: start with the 2D work you do every day, and have the 3D there for the cases that decide themselves in the volume.
Five questions worth asking any supplier
- What is the smallest field of view, and can I actually select it per case?
- What is the dose for a single-quadrant scan, in numbers I can put in a patient record?
- Does the viewing software run on the computers I already own, and how many seats are included?
- Who fixes it, from where, and what is the realistic time to site?
- What does the fifth year of ownership cost me — not the first?
If a supplier answers the last two vaguely, weigh that more heavily than any specification on the first page of the brochure.