Cone Beam CT (CBCT): 3D Imaging at Our Practice

Cone beam imaging, or CBCT (cone beam computed tomography), is a radiological examination that produces a three-dimensional image of the teeth, jaws, and surrounding structures. Unlike a conventional X-ray, which projects depth onto a flat plane, CBCT reconstructs a volume that can be explored in every direction: height, width, depth. At our Kenitra practice, this examination is performed with a Dürr Dental Cone Beam unit. It is a diagnostic and planning tool, not a treatment in itself: it helps guide decisions, it does not guarantee any outcome. This article explains what CBCT is, how it differs from a 2D X-ray, what role it plays in the implant work-up, how the question of radiation dose is handled, and above all what it does not provide.

The goal here is not to present 3D imaging as essential to every consultation, nor as a guarantee of absolute precision. CBCT is a useful examination — sometimes a decisive one — but it involves exposure to X-rays and is not indicated in every situation. Honest information means explaining both what it can and cannot do, and remembering that its use is governed by strict justification rules based on international recommendations.

# What Is a Cone Beam CT (CBCT)?

CBCT is a cone beam volumetric tomography device. During the examination, an X-ray source and a sensor rotate around the patient’s head, acquiring a series of images. A computer then reconstructs a three-dimensional volume that the practitioner can slice through and examine plane by plane. The examination is quick; the patient remains seated or standing, holding still, usually for just a few seconds.

CBCT should not be confused with a conventional medical CT scan (computed tomography). Both produce 3D images, but the technology differs: CBCT is designed for the dental and maxillofacial region, with fine resolution of bone and teeth, and it generally delivers a lower radiation dose than a medical CT scan. In the United States, the Food and Drug Administration (FDA) notes in its information sheet on Dental Cone-beam Computed Tomography that the dose from a dental CBCT is generally lower than that of other CT examinations, but higher than that of conventional dental X-rays.

# How Does CBCT Differ from a 2D X-ray or a Panoramic?

The essential difference lies in the move from two dimensions to three. A periapical X-ray or a panoramic (orthopantomogram) are two-dimensional images: they superimpose structures located at different depths onto a single plane. They are informative about the presence of decay, an infection site, or the overall condition of the teeth, but they cannot measure bone thickness or the exact position of a nerve relative to a future implant site.

CBCT, by contrast, captures the full volume. It makes it possible to measure the height and width of bone available at a specific spot, and to locate in space the structures that must be protected. It is this three-dimensional information that gives it its value in certain surgical situations.

That said, CBCT does not replace 2D examinations. On the contrary, current recommendations agree that the clinical work-up and conventional radiography come first, with CBCT stepping in only when a specific question remains unanswered. The table below summarizes these differences without imposing an absolute hierarchy: each examination has its own indication.

# What Is the Role of CBCT in the Implant Work-Up?

Implant planning is where CBCT finds one of its best-established indications. Placing an implant means answering questions that 2D imaging cannot always settle: is there enough bone, in height and thickness, to anchor the implant? Where exactly are the anatomical structures that must not be damaged?

The review of recommendations published by Jacobs et al. in 2018 in BMC Oral Health, which synthesizes the positions of the European Association for Osseointegration (EAO), recognizes the value of CBCT for pre-surgical diagnosis, pre-operative planning, and intra-operative transfer in implant rehabilitation. In the United States, the position statement of the American Academy of Oral and Maxillofacial Radiology (AAOMR), published by Tyndall et al. in 2012, goes further and considers cross-sectional imaging, including CBCT, to be the method of choice for evaluating an implant site, with the initial examination remaining the panoramic, supplemented where needed by periapical films.

In practical terms, CBCT helps analyze several key elements of the implant work-up:

• the bone volume available, in both height and thickness, at the planned site;
• the position of the inferior alveolar nerve in the lower jaw, whose protection is critical to the safety of the procedure;
• the location of the maxillary sinuses in the upper jaw, which determines in particular whether a sinus lift is needed;
• the presence of residual roots, lesions, or anatomical obstacles.

This analysis is what makes it possible, before surgery, to know whether the bone is sufficient or whether reconstruction is required. The full course of an implant placement is described in Dental Implants in Kenitra: Steps and Process, and the options when bone is lacking are detailed in Dental Implants When Bone Is Lacking: What Are the Options. The Dürr Dental Cone Beam unit used at our practice is one tool in this planning process; its presence describes a piece of equipment — it does not, in itself, constitute a guarantee of results.

# The Question of Dose: Justification and Optimization

CBCT involves exposure to X-rays. That is why it is never prescribed automatically, but always within the framework of two principles inherited from radiation protection.

# The Principle of Justification

Justification means that an examination is performed only if the expected diagnostic benefit outweighs the risk associated with radiation. These fundamental principles — justification and optimization — come from the recommendations of the International Commission on Radiological Protection (ICRP), as outlined notably in the review by Mendonça et al. (2025) on the application of ALARA and ALADA. The European SEDENTEXCT guidelines, published in 2012 by the European Commission (Radiation Protection No. 172), set a clear rule: a CBCT should only be performed after a patient history and clinical examination, and it must be justified for each individual patient, by demonstrating that the benefits outweigh the risks. CBCT is not a routine screening examination.

# The Principle of Optimization: ALARA and ALADA

Optimization means delivering the lowest dose compatible with an image that is useful for diagnosis. This is the ALARA principle (As Low As Reasonably Achievable), adapted in dental radiology as ALADA (As Low As Diagnostically Acceptable). As the review by Mendonça et al. (2025) points out, the aim is an image good enough to support a decision — not the most beautiful image possible.

This requirement matters all the more because the dose varies greatly from one device and protocol to another. The review by Jacobs et al. (2018) highlights that the effective doses of different CBCT units can be equivalent to anywhere from 2 to 200 panoramic X-rays, even for similar indications. Limiting the field of view to the area actually needed, choosing an appropriate protocol, and imaging only what is necessary are all part of this optimization. The FDA and the American Dental Association recommend performing a radiographic examination, including CBCT, only when it is necessary for diagnosis or treatment, taking into account children’s greater sensitivity to radiation.

# What CBCT Does Not Provide

An honest presentation of this examination also means stating its limits. CBCT is a tool, not a universal solution.

First, it is not indicated for everything. Many clinical situations can be resolved with a clinical examination and a 2D X-ray, without any need for 3D. Performing a CBCT in the absence of a specific indication would mean exposing the patient to radiation with no expected benefit, which runs counter to the principle of justification.

Second, it is not a guarantee of results. Precise 3D planning improves knowledge of the terrain before a surgical procedure, but it eliminates neither surgical contingencies, nor patient-related risk factors, nor the need for follow-up. CBCT informs the decision; it does not by itself make the treatment a success.

Finally, it has technical limitations of its own. The review by Jacobs et al. (2018) notes that image quality can be degraded by patient movement and by metal artifacts from existing restorations or implants, and that measurement accuracy varies between devices. Results obtained with one CBCT unit therefore do not automatically carry over to another.

# What Other Indications Are There Beyond Implantology?

The implant work-up is not the only area where 3D imaging provides a useful complement — always within the framework of a justified indication.

# Impacted Teeth

CBCT helps locate an impacted tooth precisely — a tooth that has remained in the bone, such as a wisdom tooth or a canine — and analyze its relationship to neighboring structures. For a lower wisdom tooth, it can clarify how close the root lies to the inferior alveolar nerve when the 2D X-ray leaves room for doubt, which helps assess the risk before extraction. This examination is only justified, however, in cases where 2D imaging is not enough; the extraction process is covered in Wisdom Tooth Extraction: Procedure and Recovery.

# Complex Endodontics

In root canal treatment (endodontics), CBCT can be useful in difficult situations: unusual canal anatomy, searching for an infection site not visible in 2D, suspected root fracture, or assessment of a resorption. The joint position statement of the American Association of Endodontists and the AAOMR (2015 update) frames these indications: CBCT is not recommended there as a first-line or routine examination, but is reserved for cases where conventional imaging does not provide the necessary information, favoring a limited field of view to reduce the dose.

# In Summary

Cone beam CT (CBCT) is a valuable 3D imaging examination when a specific question goes beyond what a two-dimensional X-ray can show. In the implant work-up, it makes it possible to assess bone volume and locate the inferior alveolar nerve and the sinuses before surgery; it also has a place in analyzing impacted teeth and in certain complex endodontic situations.

But it is neither a routine examination nor a guarantee of results. Its use follows two principles: justification, which reserves the examination for cases where the benefit outweighs the radiation risk, and optimization, which aims for the lowest dose compatible with a reliable diagnosis (ALARA, ALADA). At our practice, the Dürr Dental Cone Beam unit operates within this framework: a tool in the service of a considered decision, prescribed when it is useful — not simply because it is available.