A traditional dental x-ray is flat. The x-ray image shows teeth and bone as a single compressed layer, with everything in front of and behind the point of interest stacked on top of it. For most dental care that is enough. For placing a dental implant it is not.
A dental CBCT scan produces a three-dimensional model of the jaw, so bone can be measured in height, width and depth, and the nerves and sinuses can be seen in their actual positions rather than inferred. It is the difference between planning an implant and guessing at one.
What Is A Dental CBCT Scan?
CBCT stands for cone beam computed tomography. It is a form of x-ray imaging that produces 3D images of the oral and maxillofacial region: teeth, jawbone, sinuses, nerve canals and the temporomandibular joint.
The name describes the mechanism. Where a conventional dental x-ray fires a narrow x-ray beam at a flat sensor, a CBCT machine works using a cone-shaped x-ray beam that captures a whole volume of anatomy in a single scan.
The term dental cone beam CT is used interchangeably with dental CBCT, and you will also see cone-beam computed tomography written out in full. They all describe the same imaging device. CBCT systems are now standard equipment in implant dentistry and in dental radiology generally.
How Does A CBCT Scan Work?
You sit or stand still while the arm of the CBCT machine rotates once around your head, usually taking between ten and forty seconds.
During that rotation the cone-shaped x-ray beam and a detector capture between 150 and 600 individual x-ray images from different angles. Software then reconstructs those into a single three-dimensional volume that can be sliced and rotated on screen in any plane. That is the capability of CBCT that a flat film cannot match: one scan, every angle.
Nothing touches you, nothing is injected, and you are not enclosed in a tunnel. Most patients find the CBCT scan easier than a set of traditional dental x-rays, because there are no sensors held inside the mouth.
CBCT Compared With Dental X-Rays And Medical CT
Three imaging technologies get confused with one another, and the differences matter.
Traditional dental x-rays — bitewings, periapicals and panoramic images — are two-dimensional. A panoramic conventional dental x-ray shows the whole jaw in one flat picture, useful for an overview but flattening depth entirely. Bone width cannot be measured from it, and structures overlap. Dental caries and obvious pathology show well; bone architecture does not.
Dental CBCT produces 3D images from a single scan, at a fraction of the radiation of conventional CT. One rotation captures the whole volume, which is why CBCT scans provide information that no number of flat films can.
Medical CT, the kind used in hospital CT scanners, produces excellent soft tissue detail but delivers substantially higher radiation exposure and costs considerably more. Traditional medical CT equipment images soft tissue better than CBCT devices do, which is why medical CT remains the correct choice for soft tissue pathology. Conventional CT machines also image a far larger area than dental and maxillofacial work requires.
Put simply: dental x-rays show teeth, CBCT shows bone in three dimensions, and CT exams on medical computed tomography systems show soft tissue. For dental implant planning the middle one is what is needed.
Why Would A Dentist Or Periodontist Order A CBCT Scan?
Not every case needs one, and a CBCT scan should be taken because a specific question needs answering rather than as routine. Common uses of the procedure include:
- Dental implant planning: measuring bone height and width at the implant site and locating the structures to avoid
- Assessing bone loss in periodontal disease, where 3D imaging shows the shape of the defect that a flat film cannot
- Root canal assessment, where complex or additional canals are not visible on a standard x-ray image
- Impacted teeth, establishing exact position and relationship to adjacent roots and nerves
- Sinus evaluation before a sinus lift, showing the floor of the sinus and any existing pathology
- TMJ assessment and evaluation of the temporomandibular joint
- Detecting pathology such as cysts and lesions in the jaw
Across all of these the benefit of CBCT is the same: more accurate diagnoses in complex cases, from one scan rather than several.
CBCT And Dental Implant Planning
This is where the imaging technology earns its place, and it answers questions that cannot be answered any other way.
Is there enough bone? A dental implant needs adequate height and width. A panoramic image gives a rough idea of height and no information at all about width, because width runs in the dimension the image flattens.
Where is the nerve? The inferior alveolar nerve runs through the lower jaw and its position varies between patients. Damaging it causes lasting numbness of the lip and chin. On CBCT images its course can be traced and the implant planned around it.
Where is the sinus floor? In the upper back jaw, available bone height is limited by the maxillary sinus. The CBCT scan shows exactly how much there is, and whether grafting is needed before an implant can be placed.
What is the bone quality? Density varies enormously between implant sites, and it determines drilling protocol, implant selection and whether the implant can be loaded immediately.
The scan then feeds directly into digital planning software, where the implant position is designed in three dimensions before surgery. That treatment plan drives a surgical guide or real-time navigation during placement, so the position planned is the position achieved.
What Does A CBCT Scan Cost?
At our practice a CBCT scan is included in your consultation at no charge.
That is worth saying plainly, because cost is one of the most common questions about this scan and the answer elsewhere is usually a separate fee. The cost of a standalone dental CBCT scan varies widely between dental practices and imaging centers depending on the size of the field of view and the region, and patients are frequently billed for the scan before any treatment discussion has taken place.
We take the view that you should not be charged to find out whether we can help you. The scan is part of the assessment, and the assessment is how a treatment plan gets made.
Does Dental Insurance Cover CBCT Scans?
Sometimes, partially, and it depends heavily on the plan.
Coverage for cone beam technology is inconsistent across dental insurance. Some plans reimburse a portion when the scan is documented as medically necessary for a specific procedure such as implant placement or surgical planning. Others exclude 3D imaging for dental treatment entirely, or apply it against an annual maximum that the treatment itself will also draw on. Medical insurance occasionally covers a dental CBCT scan where the indication is surgical rather than dental.
Because the scan is included in your consultation with us, this question does not arise at that stage. If a further scan is needed later in treatment, our team will check your specific plan before anything is taken.
Is A CBCT Scan Safe?
CBCT uses ionizing radiation, so it carries the same category of risk as any x-ray, and it should be used when there is a reason to use it.
The dose is small. A dental CBCT scan delivers significantly less radiation than a medical CT scan of the same region, typically by an order of magnitude or more, and CBCT devices allow the field of view to be limited to just the area of interest, giving lower radiation exposure again. Dose varies with the CBCT machine, the field of view and the settings, so a small scan of one implant site is not comparable to a full skull volume.
The comparison patients usually find most useful is everyday background radiation. We are all exposed to naturally occurring radiation continuously, and a limited-field dental CBCT scan is broadly comparable to a few days of it.
The FDA and professional bodies recommend that dental cone-beam computed tomography be used only when the diagnostic question justifies it, with particular care in children. We follow that principle. If a traditional dental x-ray answers the question, we take a traditional dental x-ray.
What To Expect During And After The Scan
Preparation is minimal. You will be asked to remove jewelry, glasses, hairpins, hearing aids and any removable dental appliances, since metal creates artifacts in the images. Tell us if you are or might be pregnant.
You will be positioned with your chin on a rest and asked to stay still and not swallow while the arm rotates. The scan itself takes under a minute. There is no recovery of any kind, no sedation, and no restriction on driving or eating afterwards.
The 3D images are available immediately, which means we can look at them with you in the same appointment rather than asking you to return.
Who Interprets The Results?
The clinician who ordered the scan reviews it. In our practice that is a periodontist, and the review happens with you in the room.
This matters more than it sounds. A CBCT dataset contains a great deal of information, and interpreting bone architecture around teeth and implants is specialist work. Dental professionals differ widely in how much training they have had in reading these volumes. Periodontists spend three additional years beyond dental school on exactly the structures a CBCT scan shows: bone, the periodontal tissues, and the relationship between them.
Where a scan shows something outside our field, we refer it for a formal oral and maxillofacial radiology report.
Speak To A Periodontist
If you are considering dental implants, a 3D scan is the first real step, because until the bone has been measured nobody can tell you honestly what is possible.
Our periodontists have planned implant cases across Manhattan, Nutley, Long Island and Westchester for over twenty years. Call (347) 493-2439 or book a consultation. Your CBCT scan is included at no charge.
Common Questions
How long does a CBCT scan take? The rotation takes ten to forty seconds. The whole appointment step, including positioning, is a few minutes.
Can dentists take CBCT scans? Yes. Many general dental practices now have CBCT equipment, and dental professionals are trained in its use. What varies is how the CBCT images are interpreted and what they are used for.
Do I need a CBCT scan for a single dental implant? Usually yes. Bone width and nerve position matter as much for one implant as for several, and neither can be measured on a flat film.
Is a CBCT scan the same as a 3D dental scan? The phrase 3D dental scan is used for both CBCT and for intraoral scanning, which are different things. CBCT images bone beneath the surface. An intraoral scanner captures the visible surfaces of teeth and soft tissue. Dental implant planning uses both.
Will I get a copy of my images? Yes, on request.
