CBCT - do you always need it?

25 August 2021
3 min read
Published:

Andrew Shelley discusses the role of CBCT in implant dentistry, and provides an insight into his session for the ADI.

Andrew Shelley is a specialist in prosthodontics, a fellow of the Royal Colleges of Surgeons of Edinburgh and of England and an honorary research fellow of the University of Manchester. Andrew has a special interest in imaging prior to dental implant placement and is the author of several published papers on this topic. He is also a co-author of the FGDP(UK)’s selection criteria for dental radiography and so is ideally positioned to discuss the role of cone beam computed tomography (CBCT) in implant dentistry. Andrew has presented a session for the ADI, which has been made available to ADI members in the form of a webinar.

His session, entitled “CBCT, do you always need it?”, explores the evidence for the efficacy of CBCT imaging prior to dental implant placement. He comments, “We should start from a position that there are reasons to prescribe CBCT imaging but also reasons not to prescribe it because there is a cancer risk from exposure to ionising radiation. Therefore, we need evidence to assess the impact of having CBCT information available, especially at higher levels of efficacy such as patient outcome. We are then armed with the information we need to make a judgement on the balance of risks and benefits. I explain these levels of efficacy in my webinar.

“Current guidance is conflicting, with different recommendations in Europe compared to the USA. The American Association of Oral and Maxillofacial Radiologists (AAOMR) recommend that CBCT is used routinely prior to placement of dental implants in all sites. By contrast, the European guidance on these matters, as published by the European Association of Osseointegration (EAO), states that clinical examination and conventional radiography may be enough for some cases.”

Given the contrasting guidance and the lack of clarity regarding need for CBCT imaging in dental implantology, Andrew and his co-workers were interested to know how colleagues are currently approaching imaging prior to dental implant placement. During his webinar, in addition to discussing the risks and benefits of CBCT, Andrew shared the results of a study conducted with clinicians across the North West of England.

“We wanted to know what dentists are doing right now with regards to CBCT imaging,” he says. “I will share how we created the questionnaire and what needed to happen to acquire the most reliable information. I also discussed the results, which, not unexpectedly, demonstrated a chaotic pattern of prescription of imaging. There was no consistency in how the dentists prescribe images.

“As part of the webinar, I also presented findings of a systematic review of the available literature on the impact of prescription of three-dimensional imaging prior to dental implant placement in the anterior mandible. Studies were very limited, and their results were often conflicting.

“We therefore set up a study using phantom heads and asked colleagues to place dental implants in the mandible of models with and without the benefit of CBCT imaging. We were particularly concerned with the efficacy of imaging in preventing perforation of the anterior lingual cortex of the mandible when placing dental implants in the region. Trauma to the lingual vessels is potentially life threatening and so it’s a very serious consideration. I discussed the results and conclusions of this study in my webinar.”

Andrew also discussed a recent systematic review which addressed the placement of single dental implants anywhere in the mouth. He further discussed his own conclusions about when CBCT can be most helpful in avoiding surgical complications, based on current research and his assessment of risks and benefits. Finally, Andrew offered some practical hints and tips on how to get the best from assessment prior to dental implant placement, including ridge mapping, conventional radiographic techniques and how to maximise the information gained from CBCT images.

As technology advances and radiation dose is brought ever lower, there may come a time when the benefits of a CBCT image most often outweigh the potential risks and CBCT imaging becomes more routine. Until that time, it is critical that clinicians consider their approach in order to provide the safest and most effective dental implant treatment to their patients.

 

Andrew is in specialist practice in Manchester, UK. Qualified in 1979, he is a fellow of the Royal Colleges of Surgeons of Edinburgh and of England. He has a special interest in imaging prior to dental implant placement and is the author of several published papers on the impact of Cone Beam CT technology on treatment planning and patient outcomes.

Andrew is a co-author of the FGDP(UK)’s selection criteria in Dental Radiography.