How Does An Intraoral Scanner Work?

When a handheld pen-shaped scanner is placed in the patient's mouth and a light source is directed at the area you wish to scan, the imaging sensor captures thousands of images.

These images are processed by scanning software to generate an accurate 3D surface model of the tooth and gum geometry. This 3D model is displayed on your computer screen, allowing you to see how it is generated during the scanning process.

CAD, not a passing fad: Decades of advancements in computer-aided design/manufacturing technology have provided clinics with advanced 3D models.

Digital intraoral scanning may be new to most dental practices, but the technology itself is proven. "With the introduction of computer-aided design/computer-aided manufacturing (CAD/CAM), digital technology entered the dental and orthodontic practice," Isidora Christopoulou et al. note in the paper "Orthodontic Intraoral Scanners: A Critical Review."

The paper demonstrates how digital inventions like 3D dental scanners have ushered in the digital age of dentistry, noting that "intraoral scanners represent a significant chapter in this development and hold a very promising future." According to the FDI World Dental Federation, daily dental practice is being or will soon be impacted by new tools used by dentists and laboratory technicians specifically for digital impressions, computer-aided design, and subtractive or additive manufacturing (such as laser sintering and 3D printing, including stereolithography), all of which require good practice procedures to ensure the quality of the final product.

"Using digital impressions eliminates a series of clinical and laboratory steps, enabling the rapid and efficient delivery of the final, custom-made medical device." "

Analog impressions vs. digital impressions: Which is more accurate?

Digital impressions and dental 3D imaging software may be fast and eliminate some of the steps involved in analog impression creation, but what about the accuracy of intraoral scanners?

It's important to note that reducing the number of steps in the process itself contributes to improved accuracy, as the more steps required, the greater the chance of inadvertently introducing human error or material defects. The quality of digital scans is itself measured in terms of accuracy. We've already outlined what exactly accuracy means and how it impacts your treatment on this blog.

Today, intraoral scanners offer comparable or even better accuracy than analog impressions, and there are numerous clinical studies in this field that reinforce this. Learning how to interpret accuracy data from clinical studies is key when evaluating which scanner is best for your purposes.

In "Digital versus Traditional Dental Impressions: A Systematic Review," Chandran et al. (2019) found that 67% (16 of 24) of the studies reported that digital impressions produced by dental digital impression scanners were more accurate (in microns) than traditional impressions, and 92% (24 of 24) reported that digital impressions produced by dental digital impression scanners were more accurate (in microns) than traditional impressions. A review of studies (22 of 22 studies) showed that the clinical acceptability of digital impressions was comparable to that of traditional impressions.

A review in the Journal of Clinical and Diagnostic Research concluded that digital impressions were superior to traditional impressions based on assessments of accuracy, patient preference, and operator preference, with no statistically significant differences.