3D dentistry – the intraoral scanner
Intraoral scanners, also called intraoral scanners, are used to capture the current state of the patient's dentition and translate it into a digital model in order to reproduce the dentition. These scanners are ever more widely used in dentistry, because they make it possible to produce three-dimensional models of teeth and tissues quickly and accurately, which is necessary for many dental procedures.
The scanner is a small device that is placed in the patient's mouth and uses laser or infrared light to scan the surface of the teeth and tissues. The scanner passes slowly over the surface of the teeth, creating an accurate three-dimensional digital model that is then displayed on a computer.
The features we want to capture include the number and arrangement of the teeth, their shape, height and even the way the upper teeth contact the lower ones, i.e. the bite. For the dentist and the technician this is essential information for making crowns, veneers, splints or other restorations.
Digital three-dimensional impressions
Until now, impression materials – above all silicone, elastomeric and alginate – were used for this purpose in dentistry. Digital three-dimensional impressions not only match traditional impressions but also offer great possibilities when it comes to the planning and types of treatment. In addition, the digital copies are saved in an accessible format and can easily be delivered virtually straight to the technical laboratory. This is a significant advantage over traditional impressions, which have to be stored in an appropriate environment for a certain time and delivered physically to the dental technician – a lengthy process susceptible to external factors.
Digital impressions are immediately visualised on the computer screen. Thanks to this, the dentist can continuously monitor the state of the impression and the possible need for improvement (locally, without having to make the whole impression from scratch), as well as show the patient in an accessible way the current state of the teeth as observed by the scanner.
Comfort for the patient
Also in the scanners' favour is the reduction of patient discomfort to a minimum – there is no liquid material placed directly in the mouth, in contact with the mucosa, limiting to some degree the ability to breathe and swallow saliva while the impression is being taken. This is important especially for patients with a gag reflex.
The environmental issue is also not without significance. Favouring digital impressions over conventional ones means limiting the production of waste consisting of impression materials and their packaging (as well as the whole production trail). We discuss this topic more broadly in the article "Green dentistry".
Problems to be solved
This is not, however, a system free of flaws. Among the downsides are slight deviations of the measurement results of digitally taken impressions from the best and most precise impression materials. In addition, the device is susceptible to moisture – while taking impressions, the greatest possible dryness of the treatment field is required. The greatest challenge, however, is the high cost of the device and the need for appropriate training of the medical staff in order to make the best use of the scanner's parameters.
In 1917 the Austrian mathematician Johann Radon published a theory proving that, knowing the transform and with an infinitely large number of projections of a given image, a two- or three-dimensional image can be created. The Radon transform became the mathematical foundation of imaging. It is partly thanks to this discovery that we have today the possibility of using modern imaging equipment such as intraoral scanners. Will traditional impressions soon fall into oblivion? Over the next few years we will surely find out.
Studies
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Accuracy of Full-Arch Intraoral Scans Versus Conventional Impression: A Systematic Review with a Meta-Analysis and a Proposal to Standardise the Analysis of the Accuracy
Pesce P., Nicolini P., Caponio V. C. A., Zecca P. A., Canullo L., Isola G., Baldi D., De Angelis N., Menini M. (2025) · Journal of Clinical Medicine · systematic review and meta-analysis
Intraoral scanning often shortens the procedure and improves comfort, but full-arch accuracy depends on the scanner, the scanning strategy and the clinical situation. A digital impression is not automatically more accurate in every application.
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A double blinded trial to compare the patient satisfaction and crown accuracy of two different intraoral scanners for the fabrication of monolithic lithium disilicate single crowns
Yang C. H., Cheng C. W., Ye S. Y., Chien C. H. (2023) · Journal of Dental Sciences · prospective clinical study
Different intraoral scanners achieved clinically useful results but differed in accuracy and working time. The choice of equipment and the operator's experience matter as much as the fact that digital technology is used.