Digital impressions in orthodontics: procedure and benefits in adult treatment planning

No more trays full of paste and the gag reflex: digital impressions have profoundly transformed the start of adult orthodontic treatment in Divonne-les-Bains. In just a few minutes, a 3D intraoral scanner replaces the traditional mold.

As a follow-up to the guide on the’Discreet orthodontics for adults (lingual braces or clear aligners), This guide details a crucial link in the treatment process in 2026: taking optical impressions. You will discover its principle, how it is performed during a consultation, its precise contribution to the design of appliances, and why it has become essential in orthodontic practices. For any personal questions, an individualized opinion requires a clinical examination in the office: you can contact our team.

What is a plaster-free digital dental impression?

A plaster-free digital dental impression is a 3D model of the mouth obtained using an intraoral scanner, without any physical molding. The practitioner captures the geometry of the teeth and gums with a camera, and the digital file completely replaces the old plaster models.

In practice, the orthodontist holds a small, thin-tipped camera in their hand. They move it over the occlusal, buccal, and lingual surfaces of the teeth, while the software reconstructs a 3D model in real time, displayed on the screen. No material is injected into the mouth, no impression trays need to be bitten into, and there is no waiting for the impression to set.

Reliability documented by scientific literature

The accuracy of modern intraoral scanners is now comparable to, or even superior to, that of conventional impressions for orthodontics. An in vivo study published on PubMed Central (PMC6981254) evaluates the accuracy and precision of intraoral scanners on the complete maxillary arch, demonstrating their reliability for everyday clinical use, including on the complete arches required in orthodontics.

A digital file that can be used immediately

Unlike physical molding, which must be poured, shaped, and then shipped, the 3D file is transmitted to the laboratory or simulation software in just a few clicks. This digitalization accelerates planning, reduces manufacturing times, and allows for secure sharing between referring practitioners.

How is the optical impression taken during a consultation?

The optical impression takes place in 3 to 5 minutes per arch, without pain or injection, comfortably seated in the chair. The patient remains seated, breathes freely and can follow the live modeling on the office screen.

1. Mouth preparation

   The dental surfaces are gently dried to ensure the camera captures images without unwanted reflections. No products are injected: neither powder, as with most modern scanners, nor paste.

2. Optical scan of the first arch

   The practitioner moves the camera along the upper arch following a defined path (occlusal surface, then vestibular, then lingual). The software reconstructs the 3D model displayed on the screen in real time.

3. Scanning of the second arch and occlusion

   The same procedure is used for the lower arch. The patient then closes their teeth for a recording of the occlusion (how the jaws fit together), captured in a few seconds.

4. File validation and transfer

   The 3D model is checked on the screen, missing areas are completed by targeted scanning, then the file is validated and sent to the planning software or the laboratory.

Significantly improved comfort for sensitive patients

The elimination of the impression tray in the mouth radically changes the experience of the consultation. People with a strong gag reflex, those with a sensitive palate, or those who have difficulty breathing through their nose no longer have to dread this step. Claustrophobic or anxious patients also appreciate being able to see their mouth gradually take shape on the screen, thus demystifying the procedure.

«"In daily practice, we observe that adults who were apprehensive about traditional impressions readily accept scanning. Many are even surprised by the speed of the procedure and the accuracy of the result, which is immediately visible on the screen."»

How does this 3D technology optimize treatments for adults?

The digital impression serves as the foundation for the custom design of clear aligners and lingual braces: without it, there is no virtual simulation of the treatment. The 3D file directly feeds into the planning software which draws each planned dental movement, step by step.

For an adult seeking a discreet solution, the choice between discreet orthodontics (lingual braces or clear aligners) This approach is based on a thorough clinical analysis, of which 3D modeling is now an integral part. The practitioner remains responsible for choosing the appliance, whether it be visible braces, lingual braces, or aligners: the patient does not choose a technique alone. The digital impression is the common starting point for both techniques, each then processing the file in its own way.

Digital impressions and alginate impressions differ in several ways. A 3D digital impression takes 3 to 5 minutes per arch, is performed without paste or nausea, offers an accuracy of 20 to 50 micrometers, immediate visualization on the office screen, instant transmission to the laboratory, permanent and duplicable archiving, and allows for immediate treatment simulation. An alginate impression requires 5 to 8 minutes per arch with a setting time, often triggers a gag reflex, offers an accuracy of 80 to 150 micrometers, does not allow for visualization before pouring, requires physical shipment, a fragile and bulky model, and does not allow for simulation.

The contribution of digital technology to the design of clear aligners

Clear aligners are custom-made removable trays that gradually move teeth in successive stages. Each tray corresponds to a stage of treatment, a planned tooth movement of approximately 0.2 to 0.3 millimeters.

This level of precision is only achievable with a high-definition digital model. The planning software segments each tooth in the 3D file and then simulates the entire dental trajectory, from the initial position to the final goal. The practitioner adjusts the sequence, validates the intermediate steps, and then initiates manufacturing via 3D printing or thermoforming. Without digital impressions, this customized, serial production approach would be impossible to achieve industrially.

The precision required for custom-made lingual braces

Lingual braces are brackets bonded to the inside surface of the teeth, invisible from the outside. Unlike standardized braces, each lingual bracket is individually manufactured to fit the shape of the tooth to which it will be bonded. This requirement makes a digital impression essential.

Using the 3D file, the laboratory manufactures brackets whose base precisely replicates the contours of the lingual surface of each tooth. A bonding tray, also created from the scan, allows the practitioner to position the brackets simultaneously and with micrometric precision in the mouth. A discrepancy of just a few tenths of a millimeter in the impression would result in incorrect positioning and less effective treatment.

Facilitating dialogue with the adult patient

3D visualization also changes the practitioner-patient relationship. Even before starting, the adult sees the current position of their teeth on the screen, then the projection of the expected result. They clearly understand the necessary movements, any potential limitations of what is achievable, and can ask targeted questions. This educational transparency is particularly appreciated by a demanding adult clientele, often living near the border and accustomed to high standards of care.

Equipment that has become essential in the Pays de Gex

The Pays de Gex is among the French territories where the digitalization of orthodontic practices is most advanced, driven by an active adult clientele from across the border accustomed to Swiss healthcare standards. Intraoral scanners are now used in the majority of specialized facilities.

According to the INSEE territorial data for the Pays de Gex Agglomeration Community, The territory has surpassed 100,000 inhabitants and is experiencing sustained population growth, driven by its proximity to the Geneva basin. This dynamic generates a strong demand for specialized care, a significant portion of which concerns adult orthodontics for aesthetic and functional purposes.

Why such rapid adoption in the region?

Several factors explain the rapid deployment of digital footprinting at the Divonne-les-Bains practice. The demands of an active adult patient base, often executives in the Geneva area, are driving practices to invest in tools that minimize the time spent in the dental chair. Furthermore, Franco-Swiss patients compare practices on both sides of the border and expect a level of equipment consistent with Swiss standards.

What difference does a digital footprint make for a border-area adult?

For someone who crosses the border daily, every minute counts. A digital impression appointment fits perfectly into a lunch break, with no recovery time or lingering discomfort. The file is sent to the lab instantly, reducing the manufacturing time for aligners or lingual braces. And if the patient needs to consult a medical specialist in Switzerland (prosthetist, periodontist), the 3D file can be shared in seconds.

What are the indications for digital fingerprinting in adults?

Digital impressions are used in almost all adult orthodontic treatments, from simple aesthetic alignment to multidisciplinary cases combining orthodontics and surgery. Its use has become widespread in all planning procedures requiring an accurate model of the dentition.

Situations where further examination remains necessary

A digital impression captures the crown of the teeth and the free gum tissue, but does not assess the underlying bone, root position, or detailed periodontal health. For a complete adult orthodontic evaluation, it is combined with a panoramic radiograph, sometimes a 3D cone beam CT scan, and a clinical periodontal examination. These examinations remain essential for making a diagnosis and proposing an appropriate treatment plan.

«"The 3D file has become the cornerstone of the modern orthodontic record. It circulates between the practitioner, the laboratory, and sometimes referring specialists, but the clinical decision remains human and is based on the entire assessment carried out in the office."»

What are the concrete benefits for adult treatment planning?

Digital impressions allow for faster, more precise and more visual planning of adult orthodontic treatment, while reducing appliance manufacturing times. It transforms dialogue into consultation and secures the laboratory stages.

Saving time at every stage of the process

By combining the time savings at each stage (impression taking, transmission to the lab, manufacturing, adjustments), the treatment process for aligners can begin in a few weeks, compared to several months with the traditional approach. Once the plan is approved, the active phase of treatment unfolds with regular follow-up appointments and adjustments to the appliance before the retention device is fitted. For busy adults, this responsiveness is a decisive advantage.

About the author: Nicolas Barrière

Dr. Nicolas Barrière is an orthodontist, a qualified specialist in dentofacial orthopedics, a former hospital intern, and the founder of his practice in Divonne-les-Bains. He treats children, adolescents, and adults with orthodontic treatments (invisible aligners, lingual orthodontics), paying particular attention to the care of patients living near the French-Swiss border.

Areas of expertise: Orthodontics, Dentofacial orthopedics, Invisible aligners, Lingual orthodontics, Children's orthodontics, Adult orthodontics, Associated orthognathic surgery.

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