Thermoforming sheets or thermoplastics are an essential element in the daily work of dental clinics and laboratories. These versatile, high-precision materials enable the manufacture of customised devices such as splints, aligners, protectors and trays, adapted to the exact anatomy of each patient. Their use has transformed modern dental practice, offering fast, efficient and high-quality solutions without the need for external processes.
Over the years, thermoforming technology has evolved enormously. Current equipment allows for precise control of temperature and pressure, ensuring predictable results. Similarly, the materials available have diversified, offering different combinations of rigidity, elasticity and transparency to meet the most demanding clinical needs.
Its popularity is also due to the accessibility of the process. In just a few minutes, and with the right equipment, it is possible to manufacture functional devices with an excellent fit, reducing costs and waiting times. In addition, thermoplastic sheets stand out for their compatibility with a wide variety of treatments: from orthodontics and occlusion to aesthetics and prevention.
Let's explore what thermoplastic sheets are, how the thermoforming process works, the most commonly used types, and the keys to choosing the most appropriate one according to the type of treatment and the patient's characteristics. Don't miss it!
What are thermoplastic sheets and what are they used for?
Thermoplastic sheets are sheets made of polymeric materials that, when heated, become malleable and can be precisely adapted to a dental model. Upon cooling, they regain their rigidity and retain the acquired shape. This physical principle is the basis of dental thermoforming, a technique widely used for its simplicity, effectiveness, and customization capabilities.
These sheets are available in different diameters, thicknesses, and compositions, and can be used in both vacuum and pressure equipment. Their versatility allows for the fabrication of multiple types of intraoral devices, each with characteristics adapted to the function it will perform in the patient's mouth.
Principle of dental thermoforming
The thermoforming process begins by heating the sheet metal to a temperature that allows it to deform without losing cohesion. At this point, it is placed over a dental model (either plaster or 3D printed) and shaped using suction (vacuum) or controlled pressure.
Once cooled, the sheet retains the exact shape of the model, creating a device with a precise and stable fit. This technique combines speed, cost-effectiveness, and precision—three key factors in the manufacture of customized devices directly in the clinic or laboratory.
Clinical applications of thermoforming sheets
Thermoforming sheets play a fundamental role in various areas of dentistry. Their use has become widespread due to their adaptability to different treatments and the possibility of manufacturing durable and comfortable devices for the patient.
- Occlusal or stabilization splints: These are used to protect teeth from bruxism or to stabilize the temporomandibular joint. Thanks to thermoforming, the splints fit the dental arch perfectly, offering comfort, stability, and durability. Depending on the clinical need, they can be rigid, semi-rigid, or soft.
- Whitening trays: Thermoforming allows for the manufacture of thin, transparent trays that adapt precisely to the patient's arch. This ensures a homogeneous distribution of the whitening gel, prevents leakage, and improves the effectiveness of the treatment. Furthermore, their transparency facilitates visual monitoring during product application.
- Aligners and retainers: These are one of the most popular applications of thermoforming. Transparent sheets allow for the creation of discreet, aesthetic, and durable devices, both for progressive tooth movement (aligners) and for the retention phase following orthodontic treatment.
- Custom mouthguards: Widely used in sports, mouthguards are made with flexible sheets that absorb impacts and protect teeth and soft tissues from trauma. Thermoforming allows for complete customization, adapting them to the level of protection required according to the sport and the user's characteristics.
- Impression trays or bite registrations: In prosthodontics or oral rehabilitation, thermoplastic sheets are used to create custom-fitted trays, ensuring a more precise and comfortable impression. They are also used to manufacture intermaxillary or transfer trays.
Advantages of thermoforming compared to other methods
Thermoforming offers significant advantages over other systems for manufacturing intraoral devices:
- High precision and customisation: Each device is manufactured based on the patient's individual model, ensuring an exact fit to their dental morphology. This improves the comfort, retention and clinical effectiveness of the device, reducing the need for subsequent adjustments.
- Speed and simplicity: Thermoforming is a quick procedure: in a matter of minutes, a device ready for finishing can be obtained. This allows for a quick response to patient needs, optimising clinical workflow.
- Reduced cost: Both in materials and outsourcing of work.
- Variety of applications: The same equipment can be used to manufacture a wide variety of devices: splints, trays, protectors or aligners, maximising equipment performance and reducing outsourcing or prefabricated product purchase costs.
- Compatibility with accessible equipment: Thermoplastic sheets are compatible with a wide range of thermoforming machines (vacuum or pressure) and are easily adapted to digitalisation technologies, such as 3D printing, facilitating the integration of digital workflows.
Types of thermoforming sheets and how to choose the ideal one
The market offers a wide range of thermoplastic sheets, which vary according to their material, thickness, transparency, and clinical application. Understanding their differences is essential to guarantee optimal results.
Most common materials
- PETG (glycol-modified polyethylene terephthalate): This is one of the most widely used materials in dental thermoforming. It offers high transparency, moderate rigidity, and good dimensional stability, making it ideal for aligners, thin splints, and aesthetic trays. It is easy to manipulate, holds its shape well, and provides a smooth, glossy finish.
- EVA (Ethylene-vinyl acetate): With a softer, more elastic texture, EVA stands out for its comfort and shock absorption capacity. It is the preferred material for mouthguards and soft splints. Its flexibility improves comfort, although its transparency and rigidity are lower than those of PETG.
- Polypropylene: This semi-flexible material is highly resistant to wear and chemically stable. It is used in functional splints or devices where durability is required without sacrificing some flexibility. Its appearance is more opaque and requires specific tools for a good finish.
- Polycarbonate: This material offers high rigidity and transparency, making it suitable for hard splints or surgical guides. It withstands high loads and retains its shape during prolonged use. Precise temperature control is required during thermoforming to prevent cracking.
- Laminates or multilayers: These sheets combine different materials to obtain complementary properties, such as an inner layer of EVA for comfort and an outer layer of PETG for strength and transparency. They are widely used in hybrid splints or custom sports protectors.
Thickness and transparency
The thickness of the sheet directly influences the rigidity, flexibility, and clinical purpose of the device.
- 0.5–1 mm: whitening trays, aligners, aesthetic devices.
- 1.5–2 mm: lightweight splints or retainers.
- 2–4 mm: hard splints, sports mouthguards, or high-strength devices.
Transparency also plays a key role. Completely transparent materials are prioritized in aesthetic treatments, while colored or semi-translucent sheets can be chosen for functional devices or sports protectors.
The correct choice of thickness and degree of transparency influences both clinical function and patient acceptance.
Clear sheets vs. Mouthguard sheets
- Clear Sheets: These are the most transparent and rigid sheets, used in treatments where aesthetics and precise fit are paramount, such as aligners, splints, or whitening trays. They are formulated to maintain optical clarity after thermoforming and resist pigmentation.
- Mouthguard Sheets: These are characterized by their greater elasticity and shock absorption capacity, ideal for making sports mouthguards or soft splints. They can be available in different colors or layers, combining a soft inner layer with a more resistant outer layer.
Both types address different clinical needs, so it is important to select the material based on the end use, the required level of resistance, and patient comfort.
Take a look at the best-selling thermoforming plates:
Thermoforming sheets are a versatile, precise and cost-effective tool in modern dental practice. Their ability to adapt to multiple applications makes them an indispensable resource in both clinics and laboratories.
Selecting the right material, thickness and type is essential for obtaining devices with good fit, durability and comfort. Stiffer, more transparent sheets are ideal for splints or aligners, while more elastic sheets offer greater protection and cushioning in functional or sports devices.
Mastering the thermoforming process and understanding the properties of each material allows you to optimise time, reduce costs and offer patients customised devices with predictable, comfortable and aesthetically pleasing results.
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