Rise of the machines

15 August 2013
Volume 29 · Issue 8

Simon Garthwaite looks at the growth of 3D cone beam CT technology.

In recent years there has been a rise in the use of three-dimensional cone beam computed tomography (CBCT), and no wonder. The technology has changed the face of dentistry, offering practically unlimited views of the dentition and surrounding areas for the diagnosis and treatment of oral disease.

The CBCT images separate out individual formations for a complete 3D visualisation of the internal anatomy, allowing the identification and orientation of different tissue types as well as structures such as the sinus or even previous implants. Clinicians can gather an extraordinary amount of information about the patient without having to resort to invasive exploratory surgery.

The technology supports an array of applications including orthodontic work, implantology, fracture and periapical assessment, and maxillofacial surgeries, greatly reducing the risk of inaccurate diagnoses and improving treatment planning capabilities.

Conventional CT scanning produces a single slice image per scan, and so requires several overlapping images, which means more radiation exposure for the patient. In contrast, CBCT creates a complete volume image in a single 360-degree rotation. This technology dramatically reduces exposure time and, in turn, the risk of re-takes due to patient movement. As such, image distortion common to cephalometric scan technologies is minimised or eliminated completely.

A localised field of view is also available when using CBCT, this produces a higher resolution 3D image with exceptional clarity. Individual teeth can be examined in detail from every angle for demanding cases such as endodontic treatment or single implant placement, while exposure is confined to the smallest area and for the shortest possible duration.

Units are designed to assist patient comfort during image capture and can be adjusted to accommodate all shapes and sizes, even taking into account the need for wheelchair access. Patients find it much easier to remain still during the procedure and so avoid adversely affecting the image through involuntary movement. Leading imaging units adopt an open design, which nervous patients find more reassuring as they have direct visual contact with the operator throughout the examination.

There are a large number of applications 3D digital imaging has because the images are ‘true to life’ and can be rotated on screen to display all angles. Working with a 1:1 scale allows exact measurements for implants, accurate evaluation of bone volume and density, a precise examination of root anatomy (decreasing failure rates in endodontics), as well as the ability to define surgical protocols for cyst removals or periapical lesion treatment.

In order for any technology to be successful in dentistry, no matter how advanced, it must be easy-to-use and simple to integrate into existing practices. Fortunately, leading providers have considered these eventualities and they have produced 3D imaging equipment that is very user-friendly, with intuitive interfaces and computer-controlled systems that require minimal time and effort to learn and operate.

Pre-set programmes, automatic exposure settings and collimation reduce setup and examination time, allowing a speedier workflow and optimising time with the patient. This ease of use prevents the need for extensive staff training, making the transition to digital imaging fast, smooth and cost-effective. In addition to this, market-leading systems are usually very straightforward to install in any practice, as the units can be reconfigured to overcome any potential spatial limitations.

Without a doubt, CBCT complements advances in materials and surgical techniques and represents the pinnacle of scientific achievement for digital diagnosis, and it is becoming ever more affordable to introduce into the surgery. There are a number of solutions on the market, which provide varying degrees of quality and safety so principals would be advised to check and compare individual systems before making a purchase.