The decision to incorporate cone-beam CT (CBCT) into a dental practice is one that requires serious consideration and careful planning. In the early days of the technology, fewer sources of information existed and a community of users often shared ideas and prompted the advancement of the products. Office-based CBCT has advanced significantly since that time. It has often been described as the “gold standard” for imaging the oral and maxillofacial area and will become a part of the everyday life of most practices in the coming decades.
Rarely in the course of a person’s career does a technique or technology come along that completely transforms the way they practice. In my case, two such events have happened, the most recent of which was the in-office availability of CT. As an oral and maxillofacial surgery resident and throughout my career, I have worked with three-dimensional imaging in the hospital setting, but the inconvenience for office-based patients and the cost prohibited its use in all but the most complicated cases. Even with high-quality digital panoramic and intraoral imaging, the third dimension of dental imaging was an educated guess based on experience, technique, and “rules” that I often found to give inconsistent results. Hospital and imaging center CT scans also had significant limitations because of the inability to manipulate the data. Multiplanar reconstruction was limited to axial, coronal, and sagittal views, and no customization was offered.
The advent of three-dimensional surgical planning software for implant placement, in my opinion, opened the door for the imaging opportunities that we now have available as office-based practitioners. Even though the software required the use of a traditional fan beam CT image file and multiple conversions, it put the data in the hands of the doctor, enabling him or her to make and change treatment decisions based on information that was specific to a region of interest. Further mining of the data allowed the creation of seemingly endless possibilities for diagnosis.
As office-based procedures have become more sophisticated and expectations have risen for highly successful outcomes, immediate and accurate information has become essential for treating our patients. Several cone beam acquisition machines are now on the market and even more software products to use the data. This time is an exciting one in dentistry, when we can reach beyond the limitations of our senses and the two-dimensional world of the last century in dental radiology to see what’s really happening in the mouth and its associated hard tissues.
Determining if cone-beam CT is right for your practice
Several factors need to be taken into consideration before purchasing a cone-beam CT (CBCT) device for your practice. Like any other large capital acquisition, it needs to benefit your patients and be affordable, either by generating income or by providing such significant information that it becomes essential to patient care. Although specialty practices lend themselves best as candidates for using the information in a CBCT, general practices can also benefit greatly, especially if they perform expanded function procedures.
Although the technology has not yet been perfected for accurate caries detection using the cone beam scanner, the three-dimensional scanning of all the roots of a tooth during endodontic treatment to detect perforation or aberrant canals is useful. That application alone can prevent the loss of countless numbers of teeth each year.
The time-honored method for monitoring periodontal bone loss has been through the use of a periodontal probe and bitewing radiographs. Although this method is inexpensive, it is technique-sensitive and does not allow full visualization of the area. In addition to added visualization with CBCT images, most software includes tools for evaluating and monitoring bone density, which may help assess the effectiveness of treatment, predict the results of treatment, or identify areas of future concern.
To paraphrase the most well-known line in real estate, what are the three most important things in dental implant treatment? Location, location, and location. Anyone involved in the placement and restoration of dental implants knows this to be true. The application of CBCT has changed this area more than any other in dentistry. From three-dimensional planning to CT-directed placement to take advantage of available bone and avoid anatomic structures, the science of implantology has been revolutionized by three-dimensional imaging. Not only has it added safety and accuracy; it has minimized or eliminated the need for supportive procedures like bone and tissue grafts in many situations. Computer-generated surgical guides can be fabricated from the CBCT data to eliminate the work and possible inaccuracy of taking impressions and making traditional guide stents.
In the areas of oral surgery and oral pathology, the data from the CBCT can have a profound impact on decision making. The location and root configuration of impacted and erupted teeth can be seen with exceptional clarity. The proximity to adjacent structures can be seen and measured with digital accuracy. The extension of periapical lesions, areas of bone destruction, and involvement of the maxillary sinus are all clearly defined. Even those “spots” seen on traditional radiography can be pinpointed and diagnosed, eliminating the question of artifact and allowing the dentist to give patients definitive diagnoses.
If your practice does not incorporate enough of these situations to justify acquiring your own CBCT scanner, consideration can be given to sharing the equipment and software with an affiliated practice. Because the information gleaned from the hardware is digital, it can easily be transferred around the corner or around the world. The best arrangements, however, are when the equipment is located in the same building or within walking distance of your practice. Otherwise, you lose one of the important considerations of CBCT for your patients, and that is convenience.
An important factor in deciding to implement CBCT in your practice is whether your current office location will accommodate the hardware and software. The earliest office-based CT scanners had complex mechanical requirements and needed significant amounts of space. Modern scanners can fit in the space of a standard panoramic radiograph machine. A dedicated electric circuit is required, but no special heating, ventilation, or air conditioning is routinely needed. Laws vary from state to state regarding radiation safety, but the new machines emit less radiation than older conventional radiograph machines and scan times of less than 10 seconds will soon be routine, lowering the radiation even more. Radiation monitoring is suggested, but our experience has been that the monthly exposure is negligible.
Most CBCT scanners come with the necessary hardware and software to operate the capture station, but making the data available to other computers on your network will be your responsibility. It may not be necessary in small office situations but it is likely that you will want the ability to access the data from multiple locations, so a reliable, high-speed network should be in place in your office. If you intend to transmit images to other offices, a high-speed Internet connection will also be necessary. Currently, the size of the files and the compression available will not allow the whole file to be sent electronically, at least in a practical sense, so printing reports as portable document files (.pdf) and sending them as attachments to e-mails has been a useful tool. Data can also be placed on a CD or DVD for delivery. Many systems include the software to read and manipulate the data as a free service and the systems will copy to the disk when the data are burned.