CBCT: The New Standard of Care?

By Drs. Christine I. Peters and Ove A. Peters

“I don’t take a CBCT scan of every patient — does that mean my treatment is below the standard of care? I’m trying to save them radiation but could they sue me for that, if something goes wrong?”

The pressure on endodontists to use their cone beam machine before starting root canal treatments or endodontic surgery is palpable, but is an automatic scan of the teeth in question really in the best interest of patients?

Let us take a step back and consider the global situation in dentistry. It may seem like almost every U.S. endodontist either owns a CBCT unit or is on the verge of buying one, but that is not the case in most other countries. Dentists worldwide often do not have access to a scanner in their cities and many still use multiple angle films that require developing. In contrast to 2-D periapical images, CBCT technology has brought the great advantage of revealing 3-D views of the true anatomical situation of a patient. It avoids overlapping structures, distortion or summation of details. Dentists refer their patient for a scan at a radiologist’s office to differentiate pathosis from normal anatomy. However, is it now the new standard of care?

Attorneys define the standard of care as “that which a reasonable health care provider would or should do under similar circumstances.”

Most clinicians agree that it is advantageous and in some instances essential to take a CBCT scan before any endodontic surgery. Precise imaging becomes especially important in surgical cases that might involve vulnerable structures, including sinus cavities, nerve channels or blood vessels. CBCT scans reveal extra anatomy, relationships of structures, traumatic fractures, missed canals, resorptions, instrumentation-related issues such as perforations and help during treatment complications. Accurate measurements can replace certain working images and thus make up for the higher radiation patients receive during a CBCT scan.

3-D imaging identifies up to 40 percent more previously undetectable lesions. What do we do, now that we find so many lesions, and often asymptomatic ones? Does that mean there will an increase in the number of endodontic procedures by 40 percent as well? Pope et al. found that vital teeth vary in PDL width anywhere from 0.2 to 1 mm (1). Are we biased, because a tooth is RCT treated and CBCT shows a widened ligament? Alternatively, are we culpable for not treating such dubious teeth?

Before any impending lawsuit, a patient must prove that an avoidable negligence during treatment was the cause of his or her injury. Judges look for proof that the treatment did not meet the standard of care (2).

Legal cases could also result from a lack of ideal care or treatment. Not noting that a patient refused a recommended CBCT scan before a surgical procedure, for example, can make a clinician lose a court case. A difficult or damaging situation is considered malpractice if it could have been avoided using the right technology and clinical skill.

And this is where cone beam imaging shows its strength. It helps avoid problems by showing the true anatomy of the scanned area. That said the radiation dose is still higher than for a small number of digital PA films. The recommendation is only to use it where there are clear benefits for diagnosis and treatment, including follow-up. About half of clinicians who referred their patients for CBCT imaging changed their treatment plan. Thirty percent of practitioners chose to act instead of monitoring and extracted more teeth after viewing the images (3). It has been suggested that dentists conceive of periapical disease or health on a sliding scale, and lean towards retreatment when the radiolucency becomes medium in size. Teeth can appear flush-filled and healed on the PA but may display an over-filled obturation with a widened PDL on the CBCT. Considering patient-centered outcomes, will retreatment of these teeth improve the patient’s quality of life or their oral health? Some believe it does. However, an argument could be made, that, in some cases, non-intervention and radiographic monitoring is still a good option (4).

To answer the questions posed in the beginning: yes, CBCT may become standard of care for some therapies, but it is not necessary for every root canal treatment. CBCT is not a general screening tool. Doctors can be sued for not ordering a scan that would have circumvented injuries. They can also land in court for not documenting informed refusal. In most cases, it is not enough to talk about it; when in doubt, write it out.

Ove A. Peters, D.D.S., M.S., Ph.D., is a professor and co-Chair of the Department of Endodontics at the University of the Pacific, Arthur A. Dugoni School of Dentistry in San Francisco. He can be reached at opeters@pacific.edu. Christine I. Peters, D.D.S., is a professor in the Department of Endodontics at Pacific. She can be reached at cpeters@pacific.edu.


References

  1. Pope O, Sathorn C, Parashos P. A comparative investigation of cone-beam computed tomography and periapical radiography in the diagnosis of a healthy periapex. J Endod 2014;40:360-5.
  2. Curley AW. Dentistry, the law and CBCT. 2016 [cited; Available from: http://www.dentaleconomics.com/articles/print/volume-106/issue-10/science-tech/dentistry-the-law-and-cbct.html
  3. Mota de Almeida FJ, Knutsson K, Flygare L. The effect of cone beam CT (CBCT) on therapeutic decision-making in endodontics. Dentomaxillofac Radiol 2014;43:20130137.
  4. Liang YH, Li G, Wesselink PR, Wu MK. Endodontic outcome predictors identified with periapical radiographs and cone-beam computed tomography scans. J Endod 2011;37:326-31.