Shielding Guides

May 9, 2024

Author: Max Haydon

CBCT Radiation Protection – Optimising Radiological Protection in Dental Cone Beam Computed Tomography

Imagine a dental appointment where your dentist can virtually see inside your jaw in 3D – all in a single, quick scan. This is the promise of dental cone beam computed tomography (CBCT), a cutting-edge imaging technology revolutionising dental and maxillofacial radiology. Cone Beam Computed Tomography (CBCT) has revolutionised dental imaging, providing a detailed, three-dimensional view of the dental anatomy. This blog delves into the workings of CBCT, its applications in dental practices, and essential information on CBCT radiation protection for both patients and professionals. Throughout, we’ll also highlight how proper design and products – like Raybloc’s radiation shielding solutions support safety in dental environments.

What is Cone Beam Computed Tomography?

CBCT is a type of medical imaging technology that uses X-rays to create 3D images of the teeth, jaw, and surrounding structures. Unlike traditional 2D X-rays, CBCT offers a comprehensive view, making it a valuable tool in dental diagnostics and treatment planning.

Dental cone beam computed tomography (CBCT) is a specialised type of CT scanner designed for dental and craniofacial imaging. Unlike a conventional dental x ray that produces a flat two-dimensional image, CBCT takes a volumetric 3D image of the teeth, jaws, and surrounding structures in a single scan. It’s named for the cone-shaped X-ray beam it uses, which rotates around the patient’s head to capture hundreds of images from different angles . It’s important to clarify how cone-beam CT compares to a standard medical CT scan. A medical-grade CT scanner (often used in hospitals) employs a fan-shaped X-ray beam and spirals around the patient’s body, with the patient moving through the machine during the scan. In contrast, dental CBCT systems used by dental professionals rotate around the patient’s head with a cone-shaped beam and an area detector, capturing the entire region of interest in one rotation . The patient typically stays still while the machine moves, rather than the patient being moved through a gantry as in a conventional CT scan.

The output of a CBCT scan is similar in concept to a medical CT: both produce 3D images (a series of cross-sectional views that can be examined in any plane). However, cone-beam CT is not the same as a conventional CT in terms of technology and typical usage. CBCT generally operates at a lower X-ray energy and exposes the patient to a lower radiation dose compared to a full medical CT of the dental area . In practice, this means CBCT is superb for visualising hard tissues like bone and teeth, but it’s not ideal for distinguishing soft tissues like muscles or glands. Conventional CT or MRI might still be needed for those. In summary, dental cone-beam CT is a type of CT scanner tailored for dentistry: it uses a cone-shaped X-ray beam to rotate around the patient’s head, capturing a 3D dataset in one sweep.

X-Ray Technology and Radiation Dose in Dental Radiology

CBCT uses a cone-shaped X-ray beam, rotating around the patient’s head to capture multiple images. These images are then reconstructed into a 3D model. While the radiation dose in CBCT is generally higher than traditional dental X-rays, technological advancements and proper protocols help minimise exposure.

Uses of CBCT System in Dental Practices

CBCT is invaluable in various dental procedures. It helps in implant planning, assessing bone structure, identifying root canals, and diagnosing temporomandibular joint (TMJ) disorders. Its precise imaging capabilities assist dentists in making informed decisions and improving patient outcomes. Dental CBCT is not for every routine check-up. Instead, its power lies in providing precise 3D data for specific, often complex, cases. Its applications span across:

Surgical planning for impacted teeth: Especially wisdom teeth, where precise 3D localisation aids in safer extractions.
Diagnosing temporomandibular joint disorder (TMJ): CBCT provides clear imagery of the condyle and joint spaces.
Accurate placement of dental implants: CBCT is now the gold standard in dental implant planning, offering critical views of bone quality and nerve pathways.
Evaluation of jaw, sinuses, nerve canals, and nasal cavity: Offering a holistic view of maxillofacial anatomy.
Detecting, measuring and treating jaw tumours: Particularly when 2D imaging cannot capture the full extent of pathology.
Determining bone structure and tooth orientation: Helping orthodontists and prosthodontists plan complex cases.
Locating origin of pain or pathology: When conventional dental X-rays fall short.
Cephalometric analysis and orthodontics: Useful in planning orthognathic surgery and assessing skeletal discrepancies.
Reconstructive surgery: Aiding surgeons in building 3D models for pre-surgical planning.

Pros and Cons of Dental Cone Beam Computed Tomography

Pros

The cone – shaped x-ray beam reduces scatter radiation, resulting in better image quality.
A single scan produces a wide variety of views and angles that can be manipulated to provide a more complete evaluation.
Cone beam CT scans provide more information than conventional dental x-ray, allowing for more precise treatment planning.
CT scanning is painless, noninvasive and accurate.
A major advantage of CT is its ability to image bone and soft tissue at the same time.
No radiation remains in a patient’s body after a CT exam.
The x-rays used for CT scanning should have no immediate side effects.

Cons

The primary concern with CBCT is that it exposes patients to more radiation than standard dental radiography. There is always a slight chance of cancer from excessive exposure to radiation. A full-mouth series of intraoral X-rays or a panoramic X-ray involves only a few microsieverts of radiation, whereas a typical dental CBCT might be on the order of tens to a few hundred microsieverts.
A standard CBCT scan might expose a patient to 50–200 µSv of radiation – a small amount, but still higher than a dental X-ray. So while the risk is minimal (often quoted as one in a million), it’s not zero – and clinicians must ensure every scan is justified.
Because children are more sensitive to radiation, they should have a CT exam only if it is essential for making a diagnosis. They should not have repeated CT exams unless necessary. CT scans in children should always be done with low-dose technique.
CBCT should be used sparingly in younger patients, employing paediatric protocols, reduced fields of view, and low-dose modes wherever possible – in line with the ALARA principle: As Low As Reasonably Achievable.

Guidance on the Safe Use of Dental Cone Beam CT (Computed Tomography) Equipment

To ensure safety, dental professionals must follow strict protocols when using CBCT equipment. This includes regular maintenance and calibration, adherence to ALARA (As Low As Reasonably Achievable) principles, and shielding for both patients and staff to minimise radiation exposure.

Understanding Radiation Dose in Cone-Beam Computed Tomography

Radiation dose in CBCT varies depending on the machine settings, scanning time, and area of interest. Dental professionals should be aware of these factors, and use them effectively to balance imaging quality with minimal patient radiation exposure.

Calculating Dose and Scatter Radiation in CBCT Procedures

Scatter radiation can pose a risk during CBCT scans. To minimise this, dental practices must calculate both direct and scatter radiation doses. This includes understanding the effective patient dose absorbed and implementing shielding measures to protect both patients and staff.

Information About X-Ray Imaging for Patients

Patients should be informed about the benefits and risks associated with CBCT imaging. This includes explaining how CBCT can help diagnose dental issues and plan treatments while also emphasising the safety measures in place to reduce radiation exposure.

Radiological Protection in Dental Cone-Beam Computed Tomography (CBCT)

To enhance radiological protection, dental practices should implement proper shielding measures, adhere to guidelines set by regulatory bodies, and offer continuous education to staff on radiation safety. Raybloc offers solutions such as radiation protective doorsets and lead lined panels for walls and ceilings, which are essential for minimising radiation exposure in dental practices and ensuring the protection of patients and staff alike.

Complexities of Radiation Shielding in Dental Practices

Many dental practitioners are unaware of the complexities involved in radiation shielding, but don’t worry: Raybloc will work closely with an appointed Radiation Protection Advisor (RPA) to provide bespoke solutions, including a complete package warranting no radiation leakage for at least 10 years after installation. This comprehensive service ensures safety for all involved, giving confidence in the workplace environment.

Risks of Radiation Exposure Using CBCT

CBCT, like any X ray technology, carries radiation risks. However, following best practices, such as limiting scan time and area, using shielding, and adhering to ALARA principles, helps reduce these risks significantly.

Benefits of Using CBCT Radiation Protection

CBCT radiation protection measures ensure patient safety, reduce the risk of adverse health effects, and build trust in dental practices. Shielding, proper calibration, and education on safe imaging techniques contribute to the overall well-being of patients and staff.

The Procedure for a Dental Cone Beam CT

Getting a dental CBCT is refreshingly simple. The patient is positioned in the scanner – either seated or standing – with their head stabilised using a chin rest or headband. After stepping behind a shield, the operator triggers a quick scan that rotates once around the head. No pain, no contact – just a quiet rotation. Within moments, the 3D images are ready for analysis. Patients don’t need to fast or change routines, but will be asked to remove jewellery and any metallic objects near the face to avoid distortion in the scan.

Selection of Cone-Beam CT Equipment

When choosing a CBCT machine, dental professionals must weigh clinical needs, image resolution, field of view, and patient safety. Small-FOV systems with ultra-high resolution suit endodontists, while large-FOV models cater to implantologists and orthodontists. Features like adjustable resolution, dose-saving technology, and software compatibility are vital. And let’s not forget the room itself – installing a CBCT requires proper radiation shielding, where Raybloc (X-Ray Protection) Ltd comes in, providing compliant lead-lined walls, doors, lead- lined viewing windows, and much more.

Cone-Beam Computed Tomography General Recommendations

2D radiography or plain radiography is the imaging modality of choice. For everyday dental diagnoses – from decay to gum disease – conventional 2D X-rays remain the go-to. They expose patients to less radiation and are more than adequate for most cases.
Conducting a comprehensive clinical assessment is crucial before utilising cone beam computed tomography or any other radiation-based examination. CBCT is not for routine screening. A clinical exam and case history should guide the decision to scan – the goal is always to avoid unnecessary exposure.
Imaging with Cone Beam Computed Tomography before Implant Surgery is more useful than post-implant imaging. Planning implants with CBCT helps map vital structures, assess bone volume, and avoid complications – making it far more effective pre-surgery than simply checking the result after placement.
The effective doses for dentoalveolar cone beam computed tomography range from 11 to 674 μSv. This wide range depends on scan size and resolution. For reference, the average background radiation in the UK is about 2,700 µSv per year – meaning a CBCT adds about one to two weeks’ worth of extra exposure in many cases.
Cone beam computed tomography is appropriate in cases where a tooth is impacted, infected, or missing, and 2D radiography fails to detect the underlying pathology.
When standard imaging can’t explain the problem such as elusive root canals, impacted canines, or jaw cysts – CBCT is more accurate and is gold standard for diagnosis.
To reduce radiation exposure in children and adolescents, it is crucial to utilise dose-sparing techniques that follow the ALARA (As Low As Reasonably Achievable) principle. This includes selecting the smallest field of view, using paediatric presets, and applying lower resolution when high-definition detail isn’t essential.

Patient Radiation Safety Using CBCT Protection for Paediatric Patients

Paediatric patients require special considerations, as their developing bodies are more sensitive to radiation. Dental practices should use child-specific protocols, including adjusting machine settings, limiting scan areas, and providing additional shielding to protect young patients.

The Growing Impact of Cone Beam Computed Tomography

Over the past two decades, CBCT has reshaped the landscape of advanced dentistry. Once a luxury for specialists, it’s now a central pillar in implantology, endodontics, orthodontics, and oral surgery.According to the American Dental Association, cone-beam CT is now considered a best practice for many complex procedures such as dental implant planning and endodontic assessment.

In the UK, a report by the British Society of Dental and Maxillofacial Radiology noted that more than 60% of specialist dental clinics now have access to in-house CBCT scanners, reflecting a significant shift in clinical imaging workflows. More than just a diagnostic tool, it’s become a digital cornerstone – feeding data into virtual planning platforms, guiding surgeries, and even fuelling AI-based diagnostics. As doses continue to drop and software gets smarter, expect CBCT to grow even more indispensable – a vital blend of precision, speed, and safety in modern dental care.

The Future with Cone-Beam CT Technology and Radiation Protection

Advancements in CBCT technology and radiation protection continue to improve. Innovations like lower radiation doses, improved imaging quality, and enhanced safety measures promise a future where CBCT offers even greater benefits while minimising risks.

FAQs

Can a pregnant employee continue to work in the dental radiology department?

Yes, a pregnant employee can work in the dental radiology department, provided that radiation safety protocols are strictly followed. This includes avoiding direct exposure to X-rays and wearing appropriate shielding. Before taking risks such as these, an RPA test should have been conducted on the building in its current state to ensure it is safe.

Who may be present in the room during radiographic exposure?

Only essential personnel and the patient should be present during radiographic exposure. Protective measures, such as lead aprons or X-ray screens, should be used to shield individuals in the room.

What are the limitations of CBCT imaging?

CBCT imaging can offer comprehensive diagnostic information but is limited by its higher radiation dose compared to traditional 2D X-rays. Additionally, scatter radiation and costs associated with the equipment and its maintenance can be limiting factors.

Is a CT scan the same as a cone beam?

Not quite. Both are CT technologies, but medical CT scans (used in hospitals) employ a fan-shaped X-ray beam and higher radiation to image the whole body. Dental CBCT scans use a cone-shaped beam to capture the head and jaws in a single rotation – lower dose, focused field, and ideal for dentistry.

How do I prepare for a CBCT scan?

Preparation is minimal. No fasting needed – just remove metal from your head and neck (jewellery, glasses, dentures, etc.). If you’re pregnant or might be, let your dentist know. Wear comfortable clothes without metal collars. Beyond that, it’s just a matter of sitting still for 20–40 seconds.

How much radiation is in a cone beam CT?

A typical dental CBCT delivers between 50–200 µSv, depending on the machine and settings. That’s about the same as a few days to a few weeks of background radiation – or one or two chest X-rays. It’s far less than a medical CT, but more than a standard dental X-ray, so it should always be clinically justified.

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Max Haydon

Head of Business Development at Raybloc (X-Ray Protection) Ltd

"I’m Max, one of the Haydon brothers carrying on the family legacy of Raybloc alongside Founder (and Father), Sean Haydon. My late grandfather, Leonard Street - fondly nicknamed “Gangy” by me and my brothers - founded Raybloc alongside my dad, and their dedication to precision, proactivity, and continuous improvement inspires everything I do.

With a Master’s in Physics with Medical Physics from the University of Nottingham, I’m serious about creating valuable content for our customers but always keep things human and approachable. The most rewarding part of my job? Knowing that Raybloc’s radiation shielding systems make healthcare environments safer, improve patient experiences, and support NHS staff in reducing waiting times. It’s a great feeling to know the work we do has such a positive impact.

Outside of work, I’m usually strumming my guitar, singing along to The Beatles, or creating original music inspired by 60s and 70s legends. Looking ahead, I’m passionate about expanding Raybloc into new industries and forging partnerships with people who share our mission to make meaningful change."