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In dentistry, image is everything

Mikko Lilka is Planmeca’s Product Development Manager of Imaging Algorithms. (Photograph: Planmeca)

By Planmeca

Mon. 19 August 2019


HELSINKI, Finland: Three-dimensional dental imaging technology and software continue to make great strides when it comes to improving image quality. However, despite the progress made in the last decade, some challenges remain. So how do you achieve a great image? Planmeca’s Product Development Manager of Imaging Algorithms, Mikko Lilja, says it is a combination of three C’s: contrast, crispness and correcting artefacts.

Contrast, resolution and sharpness

In order to take a quality image, you need a high-quality imaging unit. Planmeca offers a varied range, from tried-and-true radiographic units to advanced 3-D imaging devices. Consequently, it is important to look at what kind of device suits your clinical needs, whether it is a solid workhorse unit or a full-featured, fully capable CBCT device.

Lilja said that, for dental practitioners to be able to choose the right imaging unit, they should consider devices that “have a baseline image quality—nice contrast, resolution and sharpness”. With the additional dimension provided by CBCT, a crisp 3-D image can yield an in-depth look at any area of interest, from single implant cases to the entire maxillofacial region.

Remove those pesky artefacts

Although panoramic radiographs have long been the norm in dental imaging, there is only so much one can gain from viewing a 2-D image of a 3-D structure. To achieve a great image, a CBCT imaging unit that consistently performs to a high standard is one half of the equation. The other half, however, has to do with what has traditionally been the Achilles heel of all types of dental imaging: artefacts and noise.

“When you’re imaging patients, there are all kinds of artefacts you have to deal with,” Lilja said. “There might be metal in the patient’s mouth, the patient might be moving, or you might want to use a low-dose protocol, which can add noise. So these are like an additional layer that you have to tackle to get a nice image.”

Noise reduction and metal artefact removal are standard features of Planmeca imaging units. Two years ago, Planmeca was the first dental manufacturer to introduce an end-user solution that detects and compensates for artefacts caused by patient movement: Planmeca CALM.

Motion-free image through virtual tracking

Patient movement is one of the most significant challenges to image quality, and particularly lively patients, such as children, can have a hard time keeping still for the scan. At worst, the resulting image may be diagnostically unusable, necessitating a retake and additional exposure to radiation.

Normally, if a patient moves during the scan, the image reconstruction cannot account for it, as no information regarding this movement is included in the reconstruction process. Planmeca CALM addresses this problem by taking the unwanted movement into consideration. “Basically, we are virtually tracking the motion of the patient,” explained Lilja, who is also the brains behind CALM’s algorithm.

“The algorithm ‘makes’ the C-arm of the CBCT scanner virtually follow the motion trajectory of the patient during acquisition. This makes the patient stay still in the imaging geometry, which then translates to a motion-free image,” he added.

Image is everything

In dentistry, image is everything. Before a single incision is made, a radiograph is generally taken to gauge the area of interest, make a diagnosis and decide what the appropriate course of action is. In order to obtain the best possible image for these purposes, dentists need an imaging unit that can consistently deliver the three C’s: contrast, crispness and artefact correction.

There is, however, a fourth C that could be added to the list: confidence. Specifically, the third dimension that comes with CBCT can reveal hidden pathology in the mouth and provide new insights into the present condition, improving your treatment planning—and your confidence in it. Essentially, it is about getting everything you can out of one scan and one exposure. And with all four C’s in place, the diagnostic image that you take can be a great one.

CAD/CAM Dental imaging Digital dentistry

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