Dear Patient,

Our goal is to provide you with the best, most accurate, and thorough diagnosis possible. Fortunately, recent technological breakthroughs have allowed us to make major advances in our ability to achieve that goal. The Cone Beam Computed Tomography (CBCT) (“dental cone beam” or “cone beam”) is a new technology similar to CAT scans in that it will give us a 360 degree 3 dimensional view of the area we are examining. Previously, we were limited by dental X-rays, even digital dental X-rays, to a two dimensional picture of a 3 dimensional problem. There were many things we could not see because X-rays did not have the resolution to show them. Despite our best efforts, we were forced to infer, project, surmise, calculate, and interpret. Often, we could only give our best educated guess based on what we could see on the X-ray. Additionally, X-rays were often just not sensitive enough to show very small or beginning problems. That has all changed significantly with the advent of the J. Morita dental cone beam technology. With its extremely high resolution and exceptionally low radiation, it has literally changed our world with respect to what we can now see.

Cone Beam 3D imaging offers a large volume of information and subtle details that simply cannot be obtained by any two dimensional X-ray, whether intraoral or panoramic.

One 3D scan will allow us to examine the region of interest at a high resolution from many different perspectives. Clinical studies support this technology’s improved diagnostic capabilities. We are very proud of cone beam 3D and feel strongly that this state-of-the-art technology will allow us to provide our patients with the very highest level of care possible today.

Taking the image is as simple as standing still. The 180 degree scan takes only 9.4 seconds and the images are transferred directly to a computer.

A common question about 3D imaging is the amount of radiation that is emitted in obtaining this type of image. In an effort to provide the best care and lowest radiation dose possible, we selected the Veraviewepocs 3De unit by J. Morita. This machine offers extremely low radiation exposure. In fact, J. Morita units offer the lowest radiation exposure available in the dental industry today.

Veraviewepocs 3De exposure comparisons:

• 300 times less dosage than a medical CT scan of the chest
• 15 times less dosage compared to other industry models with larger fields of view
• 8 times less dosage than a full mouth series of film X-rays (F speed)
• Dosage equivalent to less than 2 standard panoramic X-rays
• Dosage equivalent to less than 1½ times a standard, single tooth x-ray
• Less radiation than that absorbed during a flight  from Los Angeles to New York

If you have any additional questions about 3D technology, please contact our office. We would love to discuss them with you. We look forward to providing you with exceptional care utilizing the most current and advanced technology available in dentistry.

Reference: Effective dose is calculated in accordance with the ICRP
2007 Draft for exposure of the Mandibular Molar Region with Morita’s
recommended loading factor (80kV, 3mA, 9.4sec., Ø 40 x H 40 mm).
Comparison is to the Veraviewepocs film (75kV, 8mA, 16 sec). Dose
Evaluation of Dental CTs, Department of Radiology, Showa University
School of Dentistry

View the images to your left.  Nothing was moved other than the camera angle.  Can you see what moving the camera around the objects brings into view.  Just imagine an image that can see all the angles at once.  We can pick any angle to view and rotate to see all around your tooth. 

Amazing, isn't it?

The x-ray in the top left shows a  tooth that has had a root canal with a slight shadow around the end of the roots.  All the images to the right are the cone beam images.  You can see what looks like a large dark balloon surrounding the end of the roots.  Huge difference in the information available to diagnose the tooth and create the best treatment plan for the patient.

Thanks But No Thanks!

POSTED IN CBCT | APRIL 1, 2022

By Bruno Azevedo, D.D.S., M.S.

Cone Beam Computed Tomography (CBCT) has become an essential imaging diagnostic tool in endodontics.

There is an indisputable acceptance that 3D imaging is far superior diagnostically to 2D imaging. CBCT
provides more information to the clinician regarding analyzing dental and peripheral anatomy and periapical
and root pathologies. CBCT imaging also works as a scaffold for newly developed guided and dynamic
navigation surgeries and is strongly recommended before using the new irrigation systems. CBCT imaging is
also embraced in academics and is part of the educational curriculum of the next generation of endodontists in all programs in North America.

Interestingly, CBCT imaging popularity follows the same trends with other dental specialties and general
dentistry. Dental Specialties such as periodontics, orthodontics, and oral surgery rely on 3D information to
better treatment plan surgeries with surgical guides. General dentists and prosthodontists purchase and use
CBCT scans to integrate with CADCAM technology. The current scenario where different dental professionals use CBCT imaging to help their patients is favorable and allows for better comprehensive overall treatment plans. However, it raises an interesting question for the endodontic specialty. It has become more common for patients to bring CDs and jump drives to the endodontic practice with the CBCT scan acquired at the general dentist or other specialty offices. Should endodontists accept CBCT scans acquired in another practice for different diagnostic purposes?

Patients expect their current CBCT scan to provide the information needed to render the correct diagnosis and guide treatment. They don’t want to pay for another scan or be irradiated again. The problem is that in most cases, that is not true. Most CBCT scans acquired in the general dentist, and non-endodontic specialty
practices don’t have the resolution and the correct acquisition parameters to render high-resolution images
necessary to analyze the microanatomy of the pulp and interpret vertical root fractures. Endodontists must
familiarize themselves with the technical specifications of CBCT imaging acquisition to differentiate standard
scans from Endo Enhanced Advanced Imaging. To help answer this question is essential to focus on the lack of resolution and image quality and be less concerned with one’s ability to open and manipulate software. The justification of an inability to open a scan or lack of knowledge on how to use software might render a negative professional impression about the clinician by the patient.

To better understand the differences between CBCT imaging acquisition, we must differentiate the three types of CBCT scans. CBCT imaging is classified by the Field Of View (FOV). They are Large, Medium, and Small FOVs. Each FOV has different acquisition parameters, rendering different imaging quality and being used for different diagnostic purposes. Large and medium FOVs ( volumes equal to or larger than 8cm x 8cm) are acquired when the quantity of information is the purpose of the scan. They are typically used when the primary goal of the examination is to analyze the full or partial oral maxillofacial complex, including the airways, TMJs, the cervical spine, and the skull base. Due to the limitations of the imaging sensor and computational reconstruction, Large and Medium CBCT volumes are reconstructed with larger voxels. A voxel is a tridimensional pixel and is a vital parameter to help increase the spatial resolution of CBCT scans. In theory, the smaller the voxel, the better the ability to display detail; Larger and medium FOVs do not have the same ability to show detail as a small FOV scan, even if the larger FOV has the same voxel size.

Contrary to popular belief, the voxel size alone is not solely responsible for the final resolution. Larger and
medium FOVs can be acquired using the lateral-offset projection geometry, allowing a smaller sensor to image a larger anatomical area by shifting the sensor position laterally. Lateral offset projection geometry differently than the Aligned projection geometry used in small FOVs leads to more peripheral x-ray beams, which have more acute angles during the acquisition process, cause variations in the reconstruction process, and degrades image quality. Although some CBCT scans can reconstruct larger FOVs using submillimeter voxels, the final resolution is inferior to the CBCT scans acquired with smaller FOVs and identical voxels sizes. The small FOVs (volumes equal to or smaller than 6cm x 6cm) are acquired when the quality of the information is more important than the quantity of information. Smaller FOVs have the central beam of radiation aligned to the cbct sensor and provide higher accuracy and spatial resolution during image reconstruction better stable for endodontic diagnosis.

Other CBCT imaging parameters to maximize the chances of correct vertical root fracture diagnosis and the
interpretation of the microstructures related to the internal and external dental anatomy must be considered.
Tube current (mA) controls the number of photons associated with the primary radiation beam and
significantly influences the diagnostic detection of root fractures in CBCT scans. Higher mA (above 8) allows
for better visualization of root fractures when compared to scans acquired with lower mA (5 and below).
Kilovoltage (kVp) controls the penetration power of the photons. High KVp values (over 90) are indicated for
endodontic scans because they can decrease CBCT artifacts and improve overall image quality. Another critical factor is the acquisition time. Acquisition time controls the number of base images acquired during the rotation of the C-arm. The longer the acquisition time, the more base images are obtained, and the higher the CBCT scan resolution will be. Longer acquisition times also lead to significantly better vertical root fracture detection specificity and less beam hardening artifact caused by metal posts and gutta-percha. Another point to consider is the liability associated with larger FOVs which will image areas beyond the diagnostic training of nonradiologists.

Since the CBCT scans acquired in most general dentists and dental specialties offices are not optimized for
endodontic purposes, they should not be immediately accepted by the endodontic practice. There is a
significant difference between visualizing pathology surrounding a tooth versus interpreting the
microanatomy and better understanding the cause of the disease. Endodontists should inform the referring
dentists and patients that a second scan at the endodontic practice will likely be acquired. When asked why
should a second scan be acquired, the answer is simple: “Because the previous CBCT scan image quality is not enhanced for endodontic purposes. Endodontic Enhanced Advanced Imaging requires small fovs, small voxel sizes, higher kVp and mA, and longer exposure times when clinically possible. The information acquired from an Endodontic Enhanced CBCT scan far outweighs any biological risk to the patient and therefore is justified.

Please consider calling your referrals and explaining the significant differences between CBCT imaging
acquisition protocols. Sometimes it is just easier to say, “Thanks but no thanks!”

Works Cited
1. AAE and AAOMR Joint Position Statement: Use of Cone Beam Computed Tomography in Endodontics
2015 Update. Special Committee to Revise the Joint AAE/AAOMR Position Statement on Use of CBCT in
Endodontics. Oral Surg Oral Med Oral Pathol Oral Radiol 2015;120:508-12.
2. Boulos Bechara, C. Alex McMahan, Ibrahim Nasseh, Hassem Geha, Elie Hayek, Georges Khawam, MichelRaad, Marcel Noujeim, Number of basis images effect on detection of root fractures in endodontically
treated teeth using a cone beam computed tomography machine: an in vitro study, Oral Surgery, Oral
Medicine, Oral Pathology and Oral Radiology, Volume 115, Issue 5, 2013.
3. Gustavo Machado Santaella, Pedro Luiz Rosalen, Polyane Mazucatto Queiroz, Francisco Haiter-Neto,
Ann Wenzel and Rubens Spin-Neto, Quantitative assessment of variation in CBCT image technical
parameters related to CBCT detector lateral-offset position, Dentomaxillofacial RadiologyVol. 49, No. 2,
2019.
4. Pauwels R, Araki K, Siewerdsen JH, Thongvigitmanee SS. Technical aspects of dental CBCT: state of the
art. Dentomaxillofac Radiol. 2015
5. Freitas DQ, Fontenele RC, Nascimento EHL, Vasconcelos TV, Noujeim M. Influence of acquisition
parameters on the magnitude of cone beam computed tomography artifacts. Dentomaxillofac Radiol.
2018
6. Tangari-Meira R, Vancetto JR, Dovigo LN, Tosoni GM. Influence of Tube Current Settings on Diagnostic
Detection of Root Fractures Using Cone-beam Computed Tomography: An In Vitro Study. J Endod. 2017
Dr. Bruno C. Azevedo is a Board Certified oral & maxillofacial radiologist and is also known as “The Cone Beam Guy”, with his extensive experience in 3D imaging technologies in dentistry.

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