What You Need to Know

Dental cone beam computed tomography (CBCT) is a special type of x-ray machine used in situations where regular dental or facial x-rays are not sufficient. This type of CT scanner uses a special type of technology to generate three dimensional (3-D) images of dental structures, soft tissue, nerve paths and bone in the jaws and mid-lower face region, in a single scan. Images obtained with CBCT allow for more precise treatment planning.

Dental CBCT provides a fast and non-invasive way of answering a number of clinical questions. Dental CBCT images provide three-dimensional (3-D) information, rather than the two-dimensional (2-D) information provided by conventional X-ray images such as panoramic image. This helps to achieve a higher quality of diagnosis, treatment planning, evaluation of certain conditions, and more accurate procedures. In other words, the surgeon can more precisely determine where an implant can be successfully placed, evaluate pathology in a jaw, locate a problem with a tooth such as a fracture or impaction, as well as determining if there is a root resorption. These are digital images with minimal patient radiation.

Cone beam computed tomography or CBCT, is a variation of the traditional computed tomography (CT) used in medical environments. The CBCT system used in our practice captures information using a cone-shaped X-ray beam, which is then used to reconstruct a 3D image of the area of interest. The CBCT scan captures all the anatomy in one single cone shaped beam rotation, subjecting the patient to 10 times less radiation exposure. CBCT offers higher resolution, sharper images, and better metal artifact reduction compared to medical CT.
Unlike 2D scans, which are “flat” images, 3D scans allow us to completely visualize the region of interest. Like the difference between a photo and a sculpture, 3D scans give us the details we need to make more accurate diagnoses and more effective treatment plans. Major professional dental organizations recommend the use of CBCT scanning in many diagnostic and treatment planning examinations over the use of 2D intraoral radiography
During the scan, you will be positioned in the CBCT machine. For your comfort, we have chosen a Carestream Dental CBCT system, which features an open design and can accommodate patients of all sizes. A member of our team will carefully position your head and ask you to keep still during the scan. The positioning scan should only take one minute or less.
CBCT scans use a much lower radiation dose than medical CT Scans. While a medical CT scan of the jaw may expose a patient to a radiation dose equivalent to 179-578 days of background radiation, that is, the amount of radiation you are exposed to in your daily life, a CBCT scan of the same area is comparable to only 6-8 days of background radiation.

That being said, our practice only prescribes CBCT examinations when the situation calls for it. When we perform the scan, we adhere to the As Low as Reasonably Achievable (or ALARA) principle to ensure your total safety.
Lime Rays now carries the state-of-the-art 3D extraoral imaging system. Building on the award-winning 2D technology of the panoramic system, the 3D machine is a multifunction unit capable of capturing both 3D and 2D imaging.

The 3D system features one of the highest 3D image resolutions available and delivers accurate views of patient anatomy for improved diagnoses, treatment planning and surgical predictability. Users can visualize any anatomical situation from every angle, with 1:1 accuracy and without distortion or overlap of anatomy.

We are dedicated to adhering to the ALARA Principle, or, “As Low As Reasonably Achievable”, which we follow to ensure every precaution is taken to minimize patient exposure to radiation when obtaining the necessary diagnostic images needed for treatment planning. The 3D machine features Flash Scan mode to minimize dose for follow up exams and pediatrics or smaller patients. An option for all 3D programs, this setting scans in seven seconds and reduces dose by at least 50 percent over the standard acquisition.

The innovative open design of the 3D machine makes exams more comfortable and less stressful for patients.The unit also accommodates patients of all shapes and sizes, including those in wheelchairs.

Additionally, both 2D and 3D images captured by the 3D machine can be shared easily using a USB flash drive, CD/DVD, email or lightweight screen capture. To further facilitate image sharing and collaborative work, the image viewer and imaging software can be shared for free with referrals or correspondences
A panoramic radiograph is a panoramic scanning dental X-ray of the upper and lower jaw. It shows a two-dimensional view of a half-circle from ear to ear. Panoramic radiography is a form of tomography; thus, images of multiple planes are taken to make up the composite panoramic image, where the maxilla and mandible are in the focal trough and the structures that are superficial and deep to the trough are blurred.

Other nonproprietary names for a panoramic radiograph are dental panoramic radiograph and pantomogram; trade names are Panorex and Orthopantomograph (genericized versions of the latter, such as orthopantomography or orthopantomogram, are best avoided in favor of the other nonproprietary names). Abbreviations include PAN, DPR, OPT, and OPG (the latter, based on genericizing a trade name, are often avoided in medical editing).
Digital radiography is a form of X-ray imaging, where digital X-ray sensors are used instead of traditional photographic film. Advantages include time efficiency through bypassing chemical processing and the ability to digitally transfer and enhance images. Also, substantially less radiation can be used to produce an image of similar contrast to conventional radiography.

Instead of X-ray film, digital radiography uses a digital image capture device. This gives advantages of immediate image preview and availability; elimination of costly film processing steps; a wider dynamic range, which makes it more forgiving for over- and under-exposure; as well as the ability to apply special image processing techniques that enhance overall display quality of the image.
The implant fixture is first placed, so that it is likely to osseointegrate, then a dental prosthetic is added. A variable amount of healing time is required for osseointegration before either the dental prosthetic (a tooth, bridge or denture) is attached to the implant or an abutment is placed which will hold a dental prosthetic. Adequate remaining bone at the tooth extraction site is the key for success.

Success or failure of implants depends on the health of the person receiving it, drugs which impact the chances of osseointegration and the health of the tissues in the mouth. The amount of stress that will be put on the implant and fixture during normal function is also evaluated. Planning the position and number of implants is key to the long-term health of the prosthetic since biomechanical forces created during chewing can be significant. The position of an implant is determined by the position and angle of adjacent teeth or implants, the amount of existing bone and the location of anatomical landmarks such as nerve or sinus. Lab simulations or the use of Cone Beam CT scan and sometimes surgical guides called stents or templates, can help to plan for the best results. The prerequisites to long-term success of osseointegrated dental implants are healthy bone and gingiva. Since both can atrophy after tooth extraction pre-prosthetic procedures, sinus lifts or gingival grafts are sometimes required to recreate ideal bone and gingiva.

To be able to place a proper size implant in the right direction requires precise implant treatment planning and in many cases a site preparation prior to implant placement.
A surgical guide enables a clinician to place an implant more precisely and safer with minimal invasive surgery. The Glossary of prosthodontic terms (Gpt) 8, defines the surgical template, as a guide, used to assist in proper surgical placement and angulation of dental implants. The main objective of the surgical template is to direct the implant drilling system and provide accurate placement of the implant, according to the surgical treatment plan. To precisely transfer the plan to the operative site, customized conventional radiographic or computer image guided surgical templates have become a treatment of choice.

A surgical guide is the union of two components: the guiding cylinders and the contact surface. The contact surface fits either on an element of a patient′s gums or on the patient′s jaw (i.e., the bone, the teeth). Cylinders within the drill guides helps in transferring the plan by guiding the drill in the exact location and orientation. The implant must be placed such that firstly the bottom and sides are covered fully by bone or bone-replacement material. Secondly, care is taken not to damage any neighboring anatomic structures.

New techniques used for preparing the guide holes and fabricating the radiographic and surgical implant guide are conventional free-hand, milling, and computer-aided design/computer-assisted manufacture (CAD-CAM) technology.

The combination of a 3D bone model, including the 3D radiological dataset (Cone Beam CT) and the 3D radiographic guide model, enables the clinician to place implant locations according to anatomical, functional and esthetics needs and demands. In order to achieve this, the clinician virtually positions the implants, with the optimal length and diameter. Any of the modifications in 3D location and implant type, size or shape can be done in the 3D setting or in the reslice viewer. After finalizing the planning, the corresponding surgical template is designed. The surgical template thus fabricated contains all the necessary planning information-It is customized according to the location, type and size of the planned implants.