CA Pro Aligner Foil: Material Tests and First Clinical Cases

At a Glance

For Patients

The material aligners are made of affects treatment. This article describes the properties of a new aligner sheet and initial clinical applications.

For Professional Colleagues

Material properties and initial clinical applications of CA Pro aligner sheet.

Suitable Treatment at Our Practice: Clear Aligners

What is CA Pro — and why does the material matter?

Clear dental trays, called aligners, move teeth not through wires and brackets, but through the material itself: The ultra-thin plastic tray is shaped slightly differently from the current tooth position and thereby exerts gentle, continuous pressure. How well a treatment works therefore depends substantially on what the tray is made of. This is precisely where CA Pro comes in — a novel aligner film from the manufacturer Scheu Dental, introduced in this specialist publication and tested in two treatment cases.

Conventional aligners are typically made from a single plastic layer (PET-G) or multilayered polyurethane. Their typical behavior: They exert a high force initially, which, however, decreases sharply within a few hours.1 For patients, the high initial force often means an uncomfortable pressure sensation, and the rapidly declining force can make tooth movement less uniform. An ideal aligner material would therefore have a lower initial force that remains constant over a longer period.

The structure: three layers instead of one

CA Pro is constructed as a three-layer composite film (technical term: ABA film). The outer layers are two hard layers of abrasion-resistant copolyester; in the center is a soft layer of thermoplastic elastomer. This “hard-soft-hard” structure combines two properties that otherwise contradict each other: the hard outer layers provide stability and shape retention, while the soft core layer provides elasticity and uniform force delivery. According to the manufacturer, the film is available in thicknesses of 0.5, 0.625, and 0.75 mm; it is thermoformed at 150 to 175 °C. Aligners of different thicknesses can be used sequentially for each treatment step, starting with the thinner one, then the thicker one; such a sequence is suggested by a professional recommendation for aligner systems.2

What the laboratory tests show

The following values are from the publication itself (Bock et al., Journal of Aligner Orthodontics 2022; 6(3): 163–181). There, CA Pro was compared in the laboratory with a conventional aligner material — under conditions that replicate use in the mouth (bending tests in a 37 °C water bath over 24 hours).3 How much the force of conventional films decreases has also been measured by other studies; they did not examine CA Pro.1, 4 Three results are particularly relevant for practice:

• More constant force: While the conventional material retained only about 38% of its initial force after 24 hours, CA Pro retained about 51%. In absolute values, the force of the conventional material dropped from 17.4 to 6.6 newtons; for CA Pro, from 6.8 to 3.5 newtons. The force thus decreases more slowly and acts more uniformly over the wearing time.
• Lower initial force: CA Pro starts with about 40% of the initial force of the comparison material (6.8 instead of 17.4 newtons). This can increase wearing comfort, especially in the first hours after switching to a new aligner.
• Better recovery (less permanent deformation): After several loading cycles, the conventional material deformed permanently much more than CA Pro (about 70% versus about 50% of the deflection). An aligner that retains its shape better transfers its force over a longer distance of tooth movement.

Additionally, the publication tested discoloration tendency by placing samples in coffee, tea, cola, red wine, and cognac for extended periods. With CA Pro, discoloration occurred essentially only at the cut edges, not across the entire surface — an advantage for maintaining a discreet appearance during treatment. That aligner sheets discolor to varying degrees depending on the material is also shown by comparative measurements of common sheets.5

Two treatment examples from the authors’ practices

A 36-Year-Old Patient with Crowding

Case 1 was treated in the practice of co-author Dr. Björn Ludwig. A 36-year-old female patient had crowding of the front teeth in both upper and lower jaws, as well as incipient gum recession with wedge-shaped defects. Treatment was carried out with CA Pro aligners, supplemented by minimal, targeted interproximal reduction to create space and prevent further damage. The material proved noticeably more elastic than usual during insertion, which improved wearing comfort. After just ten weeks, the dental arches were visibly straightened; after a total of 16 weeks, an excellent result was achieved and secured with fixed retainers.

A 31-Year-Old Patient with In-Office Treatment

Case 2 was treated in our Cologne practice. A 31-year-old male patient wanted correction of mild crowding. His aligners were entirely planned and fabricated in the practice (in-office) — from digital impression through 3D planning to printing the models. A thorough preliminary examination with brief screening ruled out temporomandibular disorder. Over two treatment phases with a total of 24 aligners, the bite was harmonized, with the molars deliberately kept stable. After nine months, the goal was achieved and secured with a fixed retainer in the lower jaw and a night guard in the upper jaw.

What Does This Mean for Treatment?

The laboratory data suggest gentler initial force and more consistent force delivery. Both can make wearing more comfortable and support continuous tooth movement. In both cases, the planned goals were achieved without additional intermediate steps. However, these are initial clinical experiences from two cases; larger studies are needed to demonstrate long-term benefit. For aligners in general, a systematic review describes that they can achieve similar results to fixed braces for incisor inclination in mild to moderate malocclusions.6 For context: One co-author was employed by the film manufacturer during the study; this is disclosed in the publication.

For you as a patient: Aligners only work if they are worn consistently 22 hours a day, regardless of which film. Which film we use is decided after careful diagnosis, tailored to your situation. Aligners are a private service; statutory health insurance does not cover them. More on treatment with clear aligners and orthodontics for adults.

The film was also used in our virtual articulator case (0.5 and 0.625 mm, 16 weeks).