As dental professionals, we understand the importance of capturing cone-beam computed tomography (CBCT) scans to enhance our diagnoses and treatment planning; however, explaining this to patients can be challenging. I recently had the opportunity to speak with Dr. Bradley McAllister – one of the first periodontists in the Portland area to purchase a 3-D imaging system – about his selection criteria for choosing a unit. We also discussed the most common misconceptions patients have about CBCT and how he addresses these concerns.
When going through the purchasing process, what was your number one priority in a CBCT system?
For us, the most important thing was high resolution. I think it's critical in this day and age to be able to take images with high resolution so we can see the buccal plate around natural teeth and implants, as well as know exactly where critical anatomy is. It's also important for us to be able to limit the scan to the region of interest, which is why we really like the CS 9300 – it has the ability to limit the image to a really small field of vision (only five by five centimeters), or we can take a full-mouth scan, as needed, if it's a case involving multiple areas of concern.
How do you decide when CBCT scanning should be used for a case?
We do not perform CBCT scans on every patient; we use CBCT for implant cases where the anatomy needs 3-D viewing. For example, we use CBCT if the sinus is involved or if the inferior alveolar nerve is near the location where we anticipate placing implants. We also use it for visualizing periodontal defects and evaluating canine position prior to taking exposures for the orthodontist. Those are the biggest uses of CBCT in our office.
What are the attitudes of your patients toward CBCT?
The majority of our patients are really blown away by the renderings that the CS 9300 delivers and its ability to rapidly show the implant positioning. We find that it engages them and gets them involved in the treatment planning. The patient attitude toward 3-D imaging in our office has been overwhelmingly positive.
Do you ever hear any misconceptions about the technology from your patients?
The biggest misconception we hear probably regards the amount of radiation we're giving the patient. While the amount is relatively small – approximately 35 microsieverts – for a limited region of focus, many patients are concerned about the amount of radiation that a CBCT scanner uses. I think the misconception is based on historical hospital multislice CT scanners, and they did have a much higher radiation level. I think it's one of those trickle-down effects where the technology has changed by the time that people hear about it. In other words, they're reacting to 10-year-old technology and the fact that it had higher radiation.
[Note: For those interested in learning about Dr. McAllister's studies on radiography, we recommend seeking out "Clinical Applications of Digital 2-D and 3-D Radiography for the Periodontist," a paper that he wrote for the Journal of Evidence-Based Dental Practice with Dr. Thomas Eshraghi, the co-owner of Periodontal Associates.]
How do you address their concerns?
Well, we always let patients know that we don't use CBCT scans unnecessarily. Often, it is enough to say that we use CBCT scans only when we feel there is an advantage; then, we explain the benefit to the patient. Occasionally, we'll get somebody who has a high dental IQ or who works in healthcare, and we'll explain to them how background radiation is somewhere in the range of 3,000 microsieverts per year. We try to give them analogies as to how little radiation the typical 35-microsievert scan really is. Usually, that puts them at ease. At the end of the day, we always let patients make the decision.
If they choose not to have the CBCT scan, it's up to me to decide whether I can do the case. I won't do some cases without a CBCT scan because I believe it's below the standard of care. In other cases, we'll go off of our 2-D images, just like I did for the past 25 years. Most patients are usually fine with it once you discuss it with them.
Bradley McAllister, DDS, received his Doctor of Dental Surgery degree from the University of Washington and completed his periodontal specialty training and his doctorate at the University of Texas. A board-certified diplomate of the American Board of Periodontology and International Congress of Oral Implantology, he is a part-time faculty member at the Oregon Health Sciences University. Dr. McAllister can be contacted at [email protected].
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