Dental impressions and endo-oral tissues are essential for orthodontists, prosthodontists, implantologists, and all dental surgeons, for treatment planning, appliance fabrication, surgical jigging, orthodontic analysis, etc. Conventional impressions using dental materials such as alginate, impression compounds, elastomeric materials, etc. have been in use for a long time.
Recent technological advances have introduced intraoral scanners into dental practice for taking impressions and creating digital models. Intra-oral scanners (IOS) are devices that capture 3D data by parallel confocal microscopy most of the time. They are gaining popularity among dental practitioners around the world as a promising alternative to conventional impressions. This has been made possible by the advent of CAD-CAM systems for prosthesis fabrication and 3D printing. These systems use digital data to create prostheses with almost 100% accuracy and precision.
Why use a digital fingerprint scanner instead of physical-chemical fingerprints?
Digital scanners have several advantages over traditional fingerprints.
Ease of use: alginate prints are gradually becoming a thing of the past with the arrival of digital intraoral scanners, which are easier to use, quicker and very operator-friendly, unlike conventional prints, which require a great deal of skill to be made correctly.
Less patient discomfort: Intra-oral scanning minimizes patient discomfort compared to conventional physical scans, which sometimes cause coughing or gag reflexes in many patients. Research shows that 77% of patients prefer digital fingerprinting to conventional fingerprinting methods (Vasudavan et al. 2010) in terms of comfort, gag reflex and breathing at the time of fingerprinting.
Time saving: Intraoral scans have made it possible to avoid the steps of preparing materials, loading impression trays, inserting, waiting for the material to set before removing it, thus saving considerable time in the chair. When considering redoing the impression, studies have shown that the total clinical treatment time is reduced with the use of an intraoral scanner (Joda and Brägger 2016).
Precise reproduction of detail: Digital impressions capture even inaccessible areas of the oral cavity, enabling the reproduction of minute details (up to 5 microns) that cannot always be recorded on the first try with all conventional impression materials.
Transmission to dental labs instantly: All you need is fast Internet access, and you can transmit digital scans to lab technicians almost instantly.
Eliminate fabrication errors: Digital scanning eliminates the prosthesis fabrication errors that can occur due to distortion of the impression material, hygroscopic expansion of the plaster and deviation when fixing a model to an articulator. (Kihara et al. 2020)
Archiving of models : Orthodontic cases require the storage of models over a longer period of time. These models can now be easily stored on nails, accessible at any time by the operator, technicians, and even sent to specialists.
Time saving: A full arch impression can usually take 2 to 4 minutes and be transferred to the technician in a few minutes. In addition, in the event of an error, scans can be redone instantly in a few minutes without any problem. There is no need to clean the impression trays, the rubber bowl, the spatula.
Better communication with patients: Digital fingerprints make patients feel more involved in their treatment and thus contribute to more effective communication with them.
In spite of these advantages, the question that arises is this:
Are optical prints as accurate as conventional prints?
To date, the available scientific literature considers the accuracy of optical impressions to be clinically satisfactory and similar to that of conventional impressions in the case of single-tooth restorations to 4 to 5 element dentures.
The new generations of optical scanners are equipped with even more advanced technology (artificial intelligence) to eliminate artifacts automatically.
It is important to bear in mind that an intraoral scan remains for the moment a mucco-static impression. It is therefore impossible (apart from a negative impression scan) to record the trajectory of the brakes in extension, or the peripheral joint (Bimaxillary PAT).
As with any new product, there is always a learning curve to consider. Older clinicians with less experience and interest in technology generally find the adoption of new technology more complex than clinicians who are comfortable with it.
In order to be the most capable (figuratively speaking) we need to upgrade and continue to evolve over time to keep up with the new technologies that are in vogue. This is the only way to continue to succeed in the highly competitive and rapidly changing field of dentistry.
References & Quotes
Vasudavan S, Sullivan SR, Sonis AL. Comparison of intraoral 3D scanning and conventional impressions for fabrication of orthodontic retainers. ⦁J Clin Orthod⦁. 2010;44(8):495-497.
2. Joda T, Brägger U. Patient-centered outcomes comparing digital and conventional implant impression procedures: a randomized crossover trial. Clin Oral Implants Res. 2016;27(12):e185-e189.
3. Kihara H, Hatakeyama W, Komine F, et al. Accuracy and practicality of intraoral scanner in dentistry: A literature review. J Prosthodont Res. 2020;64(2):109-113.
4. Ahmed KE, Wang T, Li KY, Luk WK, Burrow MF. Performance and perception of dental students using three intraoral CAD/CAM scanners for full-arch scanning. J Prosthodont Res. 2019;63(2):167-172.
5. Mangano F, Gandolfi A, Luongo G, Logozzo S. Intraoral scanners in dentistry: a review of the current literature. BMC Oral Health. 2017;17(1):149.