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Fabrication of Transparent Orthodontic Aligners
For many people, the idea of orthodontic treatment comes with one big concern—how it will affect their appearance. While straightening teeth is important not just for aesthetics but also for oral health, most patients would prefer a solution that doesn’t stand out. That’s why clear aligners have become so popular. They offer a nearly invisible way to achieve a better smile without the look of traditional braces.
As demand for clear aligners continues to grow, more orthodontists are integrating them into their practice. But what exactly makes these aligners work? In this article, we’ll explore the materials, fabrication process, and benefits of transparent aligners.
What are Transparent Orthodontic Aligners?
Transparent orthodontic aligners are a modern alternative to traditional braces, offering a nearly invisible and comfortable way to straighten teeth. Made from clear, flexible plastic, these aligners are custom-designed to fit over a patient’s teeth and gradually guide them into alignment. Unlike braces, they do not require metal brackets or wires, making them a more aesthetic and convenient option for many patients.
The idea of using clear aligner for orthodontic treatment dates back to 1945, but significant advancements only came with the rise of digital dentistry. The introduction of 3D scanning, CAD/CAM technology, and 3D printing has transformed the way aligners are designed and manufactured. Instead of relying on physical impressions, orthodontists now use digital scans to create highly precise treatment plans. Each step of tooth movement is mapped out in specialized software, and a series of aligners is 3D-printed to follow this plan.
Materials Used in Transparent Orthodontic Aligners
The performance and comfort of clear aligners largely depend on the materials used in their fabrication. The ideal aligner material should:
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Deliver gentle yet effective force over the recommended wear period.
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Be comfortable to wear and easy to insert and remove.
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Maintain its transparency throughout the treatment process.
The manufacturing process also plays a crucial role in determining aligner material properties. Currently, most clear aligners are produced using vacuum thermoforming on physical models.
Thermoplastic Polymers
Thermoplastic polymers are the most commonly used materials in dental aligners manufacturing. The most widely used polymers in clear aligners include:
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Polyesters: PET (polyethylene terephthalate) and PETG (polyethylene terephthalate glycol) are favored for their excellent mechanical strength, durability, and transparency.
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Polyurethane (TPU): TPU provides flexibility, elasticity, and resistance to wear, allowing aligners to maintain their shape while delivering continuous force.
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Polycarbonate, polypropylene, ethylene vinyl acetate, and polyvinyl chloride: These materials are often blended to enhance specific mechanical properties.
Aligner materials have evolved from single-layer plastic to multilayered structures. Modern materials incorporate both soft and hard layers to improve elasticity, durability, and patient comfort.
Polymer Blends
Combining different polymers can enhance the physical properties of clear aligners. Blending materials like PETG, polycarbonate, and TPU in specific ratios improves mechanical strength and provides sustained orthodontic forces.
3D-Printed Aligner Materials
Direct 3D printing is emerging as an alternative to thermoforming, potentially improving geometric accuracy and mechanical performance. Materials used in 3D-printed aligners include:
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Photopolymer resins (e.g., Tera Harz TC-85) designed for direct aligner printing.
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Other experimental materials such as acrylonitrile-butadiene-styrene (ABS), polylactic acid (PLA), and nylon.
While promising, most 3D-printed aligner materials are still undergoing research and development to meet biocompatibility, mechanical strength, and transparency requirements.
Bioactive Materials for Clear Aligners
Since transparent orthodontic aligners are worn almost continuously, they can create an environment conducive to bacterial growth. Researchers are exploring antimicrobial coatings and bioactive materials to reduce plaque buildup and improve oral health. For example, coating aligners with gold nanoparticles (AuDAPT) has shown potential in slowing bacterial growth and biofilm formation.
Fabrication Process of Transparent Orthodontic Aligners
The fabrication of orthodontic aligners follows a precise digital workflow that ensures accuracy, efficiency, and customization for each patient. The process consists of several key stages.
Digital Data Collection
The fabrication process begins with collecting precise digital data of the patient’s dentition. This step involves 3D intraoral scanning, which captures an accurate digital impression without the discomfort of traditional molds. High-resolution photographs are also taken to document the patient's initial smile and facial profile. In some cases, CBCT scans may be used to provide a more detailed view of bone structures, particularly when complex orthodontic movements are required.
Digital Design
Once digital records are collected, they are processed in specialized orthodontic software to create a step-by-step treatment plan. This involves designing controlled tooth movements, predicting outcomes, and ensuring precise aligner fit.
eXceed simplifies this process by providing precise treatment planning. Clinicians are not required to have a digital design expertise—eXceed’s trained design planners handle the mapping process. Every plan undergoes a review by experienced orthodontists.
3D Printing of Model Stages
Each step of the treatment corresponds to a unique 3D-printed model that serves as a base for thermoforming individual aligners. The digital treatment plan is translated into a series of physical models, each representing a progressive stage of tooth movement. These models are printed using 3D printers that ensure dimensional accuracy, which is critical for aligner effectiveness.
Post-Processing
After printing, the models undergo a post-processing phase to remove excess material and ensure smooth edges. This step involves cutting and refining printed models to remove any residual supports or imperfections from the printing process. Properly processed models help achieve optimal fit and comfort when aligners are thermoformed.
Thermoforming
Aligners are fabricated using a vacuum thermoforming process, where a thin, transparent thermoplastic sheet is heated and molded over the 3D-printed model. The process is similar to fabrication of custom-made mouth guards.
The material selection is critical, as it determines the aligner's strength, elasticity, and clarity. Once formed, the aligner retains the precise shape of the model, allowing it to exert controlled forces on the teeth when worn by the patient.
Final Processing
Following thermoforming, each aligner is trimmed to remove excess plastic and ensure a smooth, comfortable fit. Edges are polished to prevent irritation to the patient’s gums and soft tissues. The final adjustments ensure that the aligners maintain their shape, strength, and aesthetics throughout the wear period.
Packaging and Quality Control
Before reaching the patient, aligners undergo a quality control process to verify their fit, clarity, and durability. Once approved, they are carefully packaged in sequential sets, ensuring that patients receive their aligners in the correct order for treatment progression.
Chairside Adjustments and Recommendations
In some cases, additional in-office adjustments are necessary to enhance treatment efficiency. Orthodontists may place attachments—small tooth-colored composite bumps—on select teeth to facilitate complex movements. Patients are then guided on how to wear and maintain their aligners.
Advantages of Transparent Orthodontic Aligners
Discreet Treatment for a Confident Smile
One of the main reasons patients choose clear aligners is their nearly invisible appearance. Unlike traditional braces, which use metal brackets and wires, aligners allow patients to undergo orthodontic treatment without drawing attention to their teeth.
No Dietary Restrictions
Braces often come with a long list of foods to avoid—sticky candies, hard fruits, crunchy snacks—all to prevent damage to the brackets and wires. Clear aligners eliminate these concerns. Since they are removable, patients can enjoy their favorite foods without limitations.
Improved Oral Hygiene
Traditional braces make brushing and flossing more challenging, often leading to plaque buildup and an increased risk of cavities. Clear aligners allow patients to maintain their usual oral hygiene routine, as they can be taken out for thorough brushing and flossing.
Enhanced Comfort
Patients who have worn both braces and aligners often report that aligners are significantly more comfortable. The smooth plastic surface prevents irritation to the gums and inner cheeks, unlike metal brackets and wires, which can cause sores and discomfort. Additionally, aligners exert gentler, more controlled forces on the teeth, reducing overall pain levels during treatment.
Highly Predictable Results
Clear aligner treatment is based on advanced digital planning. Each aligner is designed to move the teeth according to a precise, pre-planned sequence.
Lower Risk of Complications
Braces come with certain risks—brackets can detach, wires may break, and improper force application can lead to unexpected tooth movements. These issues can cause discomfort and require emergency orthodontic visits. Clear aligners, on the other hand, minimize these risks.
Indications and Contraindications
While clear aligners offer numerous advantages, they are not a universal solution for all orthodontic cases. Each aligner brand has its own capabilities and limitations, and treatment success depends on proper case selection.
eXceed aligners are effective for:
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Diastema up to 6.0 mm
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Closing gaps & mild-to-moderate crowding (≤6.0 mm)
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Tooth rotation & expansion
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Crossbite correction (anterior & premolars)
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Space retention & relapse treatment
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Pre-orthopedic treatment preparation
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Retention solutions (passive, active, double)
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Deep bite correction
However, aligners are not recommended for:
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Severe spacing/crowding (>6.0 mm)
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Expansion/distalization beyond 1.5 mm
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Class III malocclusion
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Torque & distal inclination control
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Deciduous or partially erupted teeth
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Active periodontal disease
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Bruxism, TMJ issues, or hypersensitivity to aligner materials
How to Choose the Right Transparent Aligners?
Selecting an aligner provider for your clinic requires a careful evaluation of key factors that impact treatment quality, workflow efficiency, and overall cost-effectiveness. Here’s what to consider:
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Reliability and Quality – The effectiveness of aligner treatment depends on the quality of materials used. Look for providers that offer durable, stain-resistant, and biocompatible thermoplastic materials. The manufacturing process should ensure precise fit and consistent force application for predictable tooth movement.
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Treatment Scope – Different aligner brands are designed for different orthodontic cases. Review the specific indications and limitations of each provider to ensure they align with the types of cases you commonly treat.
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Equipment Compatibility – If you produce aligners in-house, check whether the provider’s workflow integrates with your existing equipment, including 3D scanners, printers, and thermoforming machines.
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Flexible Services – A brand with adaptable solutions can improve efficiency and reduce costs. eXceed, for example, offers a unique concept among aligner providers: pay for what you really need. Clinics that have their own production capabilities can opt for treatment planning only, significantly reducing the costs of aligner production.
Maintenance and Care Tips
To keep aligners effective and hygienic, follow these simple guidelines:
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Clean daily – Rinse aligners with warm water and use a soft toothbrush with mild soap or specialized product (washing liquid, tablets, foam) for orthodontic protection device.
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Avoid staining – Remove aligners before eating or drinking anything except water.
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Store properly – Always keep aligners in their case when not in use to prevent damage or loss.
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Handle with care – Use gentle pressure when inserting or removing aligners to avoid cracking.
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Maintain oral hygiene – Brush and floss before wearing aligners to prevent plaque buildup.
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Follow your doctor’s recommendations – Adhere to scheduled visits and specific instructions regarding wear time, attachments, and refinements.
