MalocclusionTPU-ALIGNNCT07566533
Comparison of Single-Layer and Triple-Layer TPU MaxFlex Aligners After Intraoral Use
A study testing Single-Layer Thermoplastic Polyurethane Aligner and Triple-Layer Thermoplastic Polyurethane Aligner in people with Malocclusion and Orthodontic Treatment, run by Ayub Medical College, Abbottabad at 1 site in Pakistan.
Trial summary
This study aims to compare two types of clear orthodontic aligner materials used in dental treatment: single-layer and triple-layer thermoplastic polyurethane (TPU) aligners (MaxFlex). Clear aligners are commonly used to straighten teeth and are preferred for their comfort and aesthetic appearance. Read more about this study
- Who is it for?
- Ages 18 to 30 years
- Conditions the study is for
- Malocclusion, Orthodontic Treatment, Clear Aligner Therapy
- What is being tested?
- Single-Layer Thermoplastic Polyurethane Aligner and Triple-Layer Thermoplastic Polyurethane Aligner
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 66 participants
- Where
- 1 sitePakistan
- Study dates
- 13 Sep 2025to 16 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patients aged 18-30 years Fully erupted permanent dentition Good periodontal health Patients undergoing orthodontic treatment with clear aligners Mild crowding or spacing requiring labiolingual tooth movement Willingness to wear aligners for at least 22 hours per day Provision of informed consent
Who cannot join
- Use of aligners from manufacturers other than study-specific TPU aligners Damaged or fractured aligners Poor compliance (wear time less than 22 hours/day) Presence of parafunctional habits (e.g., bruxism) Hypodontia or partially erupted dentition Cases involving bonded attachments on maxillary incisors Cases requiring rotational movement of maxillary incisors Patients with systemic or oral conditions affecting saliva composition or the oral environment
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Intraoral Aging on Mechanical Properties and Surface Morphology of Single-Layer Versus Triple-Layer Thermoplastic Polyurethane (TPU) MaxFlex Aligner Sheets: A Randomized Controlled Trial
This study aims to compare two types of clear orthodontic aligner materials used in dental treatment: single-layer and triple-layer thermoplastic polyurethane (TPU) aligners (MaxFlex). Clear aligners are commonly used to straighten teeth and are preferred for their comfort and aesthetic appearance.
Participants will be provided with aligners and instructed to wear them for approximately 22 hours per day for 10 days. The aligners will be collected before use and after the 10-day period. The study will evaluate how the oral environment affects the properties of these materials over time.
Laboratory tests will be conducted to measure mechanical properties such as strength, flexibility, and deformation, as well as to examine surface changes under a microscope. The results of this study may help improve the performance and durability of aligners and contribute to better orthodontic treatment outcomes.
Read the detailed description
Clear aligner therapy (CAT) has become an increasingly popular alternative to fixed orthodontic appliances due to its aesthetic advantages, improved patient comfort, and ease of oral hygiene maintenance. Thermoplastic materials, particularly thermoplastic polyurethane (TPU), are widely used in the fabrication of aligners due to their favorable mechanical and elastic properties.
Recent advancements in aligner materials have led to the development of multilayer TPU systems designed to enhance flexibility, force delivery, and clinical performance. Triple-layer TPU aligners typically consist of a soft inner layer for patient comfort, a rigid intermediate layer for structural strength, and a flexible outer layer to improve adaptability and fit. In contrast, single-layer TPU aligners are composed of a homogeneous material and are generally more cost-effective.
Despite these developments, limited evidence exists regarding the comparative behavior of single-layer and multilayer TPU materials following intraoral exposure. The oral environment, characterized by temperature fluctuations, moisture, masticatory forces, and enzymatic activity, may contribute to material degradation, potentially affecting aligner performance.
This randomized controlled trial is designed to evaluate the effects of intraoral aging on the mechanical properties and surface morphology of single-layer and triple-layer TPU aligners (MaxFlex). Participants will be randomly assigned to receive one type of aligner material and will be instructed to wear the aligners for a standardized duration of 10 days (minimum 22 hours per day).
Aligners will be collected at baseline (prior to intraoral use) and after the 10-day wear period. Following retrieval, samples will undergo standardized cleaning procedures before laboratory analysis.
Mechanical testing will be performed using dynamic mechanical analysis to assess tensile properties, stress relaxation behavior, and creep characteristics. Surface morphology will be evaluated using scanning electron microscopy to identify features such as roughness, cracks, and voids. Additionally, Fourier transform infrared spectroscopy will be used to detect potential chemical changes in the material composition.
The primary objective of this study is to compare the mechanical performance of single-layer and triple-layer TPU aligners before and after intraoral use. Secondary outcomes include evaluation of surface morphology and chemical structure changes associated with intraoral aging.
The findings of this study are expected to provide insight into the durability and clinical performance of different aligner materials, which may help guide material selection and improve orthodontic treatment outcomes.
- Conditions
- Malocclusion, Orthodontic Treatment, Clear Aligner Therapy
- Being tested
- Single-Layer Thermoplastic Polyurethane Aligner, Triple-Layer Thermoplastic Polyurethane Aligner
- Keywords
- Thermoplastic Polyurethane (TPU), Clear Aligners, MaxFlex Aligners, Intraoral Aging, Scanning Electron Microscopy (SEM)
- Medical subject headings
- Malocclusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Single-Layer Thermoplastic Polyurethane AlignerDevice
Single-layer thermoplastic polyurethane (TPU) clear aligners fabricated from a homogeneous TPU sheet using thermoforming techniques. These aligners are designed to deliver orthodontic forces for tooth movement. Participants will be instructed to wear the aligners intraorally for 10 days for a minimum of 22 hours per day. The aligners will be evaluated before use and after intraoral exposure to assess changes in mechanical properties and surface morphology.
Triple-Layer Thermoplastic Polyurethane AlignerDevice
Triple-layer thermoplastic polyurethane (TPU) clear aligners composed of a multilayer structure including a soft inner layer, a rigid intermediate layer, and a flexible outer layer. These aligners are fabricated using thermoforming techniques and are designed to provide improved force delivery and adaptability. Participants will wear the aligners intraorally for 10 days for at least 22 hours per day. Pre- and post-use evaluations will be conducted to assess mechanical properties and surface morphology changes.
| Study group | Role | What they receive |
|---|---|---|
| Single-Layer TPU Aligner Group | Experimental | Participants in this group will receive single-layer thermoplastic polyurethane (TPU) MaxFlex aligners. The aligners will be worn intraorally for 10 days for a minimum of 22 hours per day under standardized conditions. Aligners will be collected at baseline and after the wear period for evaluation of mechanical properties and surface morphology. Receives: Device: Single-Layer Thermoplastic Polyurethane Aligner |
| Triple-Layer TPU Aligner Group | Experimental | Participants in this group will receive triple-layer thermoplastic polyurethane (TPU) MaxFlex aligners consisting of a soft inner layer, a rigid intermediate layer, and a flexible outer layer. The aligners will be worn intraorally for 10 days for a minimum of 22 hours per day. Aligners will be collected at baseline and after use for mechanical and surface analysis. Receives: Device: Triple-Layer Thermoplastic Polyurethane Aligner |
What is being measured
The primary outcome is the main question the study is designed to answer.
Effect of Oral Environment on Elastic Modulus of TPU Aligners
This outcome measures the change in elastic modulus (MPa) of thermoplastic polyurethane (TPU) orthodontic aligners following intraoral exposure. Measurements are obtained using a dynamic mechanical analyzer and compared between single-layer and multilayer TPU aligners at baseline and after two weeks of clinical use to assess changes in stiffness and material integrity.
Measured: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
Effect of Oral Environment on Stress Relaxation of TPU Aligners
This outcome measures the percentage stress relaxation (%) of TPU aligners following intraoral exposure. Stress decay over time is recorded using a dynamic mechanical analyzer and compared between single-layer and multilayer TPU aligners at baseline and after two weeks to evaluate force retention capacity.
Measured: Time Frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
Effect of Oral Environment on Creep Behavior of TPU Aligners
This outcome measures creep (% strain) in TPU aligners under constant stress conditions using a dynamic mechanical analyzer. Comparisons are made between single-layer and multilayer TPU aligners at baseline and after two weeks to assess susceptibility to permanent deformation.
Measured: Time Frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 May 2026
- Study start13 Sep 2025
- Primary completion5 Mar 2026
- Study completion16 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MalocclusionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomly assigned to one of two parallel groups receiving either single-layer or triple-layer thermoplastic polyurethane (TPU) aligners (MaxFlex). Each participant will use the assigned aligner type for 10 days under standardized conditions (minimum 22 hours per day), after which the aligners will be retrieved for laboratory analysis.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 66 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ayub Medical College, Abbottabad
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Abdul Qadir, Akhtar Saeed Medical and Dental College
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07566533
- Sponsor's protocol ID
- TPU-ALIGNER-01
- Other IDs
- no identifier
- Acronym
- TPU-ALIGN
- Status last verified
- Sep 2025
- First submitted
- 19 Apr 2026
- Last updated
- 5 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 5 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Intraoral Aging on Mechanical Properties and Surface Morphology of Single-Layer Versus Triple-Layer Thermoplastic Polyurethane (TPU) MaxFlex Aligner Sheets: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07566533
- Acronym / sponsor ID
- TPU-ALIGN / TPU-ALIGNER-01
- Conditions
- Malocclusion, Orthodontic Treatment, Clear Aligner Therapy
- Keywords
- Thermoplastic Polyurethane (TPU), Clear Aligners, MaxFlex Aligners, Intraoral Aging, Scanning Electron Microscopy (SEM)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 66 participants (actual)
- Lead sponsor
- Ayub Medical College, AbbottabadUniversity, hospital or other
- Study start
- 13 Sep 2025 (actual)
- Primary completion
- 5 Mar 2026 (actual)
- Study completion
- 16 Mar 2026 (actual)
- First posted
- 5 May 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study aims to compare two types of clear orthodontic aligner materials used in dental treatment: single-layer and triple-layer thermoplastic polyurethane (TPU) aligners (MaxFlex). Clear aligners are commonly used to straighten teeth and are preferred for their comfort and aesthetic appearance.
Participants will be provided with aligners and instructed to wear them for approximately 22 hours per day for 10 days. The aligners will be collected before use and after the 10-day period. The study will evaluate how the oral environment affects the properties of these materials over time.
Laboratory tests will be conducted to measure mechanical properties such as strength, flexibility, and deformation, as well as to examine surface changes under a microscope. The results of this study may help improve the performance and durability of aligners and contribute to better orthodontic treatment outcomes.
Detailed description
Clear aligner therapy (CAT) has become an increasingly popular alternative to fixed orthodontic appliances due to its aesthetic advantages, improved patient comfort, and ease of oral hygiene maintenance. Thermoplastic materials, particularly thermoplastic polyurethane (TPU), are widely used in the fabrication of aligners due to their favorable mechanical and elastic properties.
Recent advancements in aligner materials have led to the development of multilayer TPU systems designed to enhance flexibility, force delivery, and clinical performance. Triple-layer TPU aligners typically consist of a soft inner layer for patient comfort, a rigid intermediate layer for structural strength, and a flexible outer layer to improve adaptability and fit. In contrast, single-layer TPU aligners are composed of a homogeneous material and are generally more cost-effective.
Despite these developments, limited evidence exists regarding the comparative behavior of single-layer and multilayer TPU materials following intraoral exposure. The oral environment, characterized by temperature fluctuations, moisture, masticatory forces, and enzymatic activity, may contribute to material degradation, potentially affecting aligner performance.
This randomized controlled trial is designed to evaluate the effects of intraoral aging on the mechanical properties and surface morphology of single-layer and triple-layer TPU aligners (MaxFlex). Participants will be randomly assigned to receive one type of aligner material and will be instructed to wear the aligners for a standardized duration of 10 days (minimum 22 hours per day).
Aligners will be collected at baseline (prior to intraoral use) and after the 10-day wear period. Following retrieval, samples will undergo standardized cleaning procedures before laboratory analysis.
Mechanical testing will be performed using dynamic mechanical analysis to assess tensile properties, stress relaxation behavior, and creep characteristics. Surface morphology will be evaluated using scanning electron microscopy to identify features such as roughness, cracks, and voids. Additionally, Fourier transform infrared spectroscopy will be used to detect potential chemical changes in the material composition.
The primary objective of this study is to compare the mechanical performance of single-layer and triple-layer TPU aligners before and after intraoral use. Secondary outcomes include evaluation of surface morphology and chemical structure changes associated with intraoral aging.
The findings of this study are expected to provide insight into the durability and clinical performance of different aligner materials, which may help guide material selection and improve orthodontic treatment outcomes.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Participants will be randomly assigned to one of two parallel groups receiving either single-layer or triple-layer thermoplastic polyurethane (TPU) aligners (MaxFlex). Each participant will use the assigned aligner type for 10 days under standardized conditions (minimum 22 hours per day), after which the aligners will be retrieved for laboratory analysis.
| Arm | Type | Receives |
|---|---|---|
| Single-Layer TPU Aligner Group | Experimental | Device: Single-Layer Thermoplastic Polyurethane AlignerParticipants in this group will receive single-layer thermoplastic polyurethane (TPU) MaxFlex aligners. The aligners will be worn intraorally for 10 days for a minimum of 22 hours per day under standardized conditions. Aligners will be collected at baseline and after the wear period for evaluation of mechanical properties and surface morphology. |
| Triple-Layer TPU Aligner Group | Experimental | Device: Triple-Layer Thermoplastic Polyurethane AlignerParticipants in this group will receive triple-layer thermoplastic polyurethane (TPU) MaxFlex aligners consisting of a soft inner layer, a rigid intermediate layer, and a flexible outer layer. The aligners will be worn intraorally for 10 days for a minimum of 22 hours per day. Aligners will be collected at baseline and after use for mechanical and surface analysis. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Patients aged 18-30 years Fully erupted permanent dentition Good periodontal health Patients undergoing orthodontic treatment with clear aligners Mild crowding or spacing requiring labiolingual tooth movement Willingness to wear aligners for at least 22 hours per day Provision of informed consent
Key exclusion criteria (1 listed)
- Use of aligners from manufacturers other than study-specific TPU aligners Damaged or fractured aligners Poor compliance (wear time less than 22 hours/day) Presence of parafunctional habits (e.g., bruxism) Hypodontia or partially erupted dentition Cases involving bonded attachments on maxillary incisors Cases requiring rotational movement of maxillary incisors Patients with systemic or oral conditions affecting saliva composition or the oral environment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Single-Layer Thermoplastic Polyurethane AlignerSingle-layer thermoplastic polyurethane (TPU) clear aligners fabricated from a homogeneous TPU sheet using thermoforming techniques. These aligners are designed to deliver orthodontic forces for tooth movement. Participants will be instructed to wear the aligners intraorally for 10 days for a minimum of 22 hours per day. The aligners will be evaluated before use and after intraoral exposure to assess changes in mechanical properties and surface morphology. | Device | Single-Layer TPU Aligner Group |
| Triple-Layer Thermoplastic Polyurethane AlignerTriple-layer thermoplastic polyurethane (TPU) clear aligners composed of a multilayer structure including a soft inner layer, a rigid intermediate layer, and a flexible outer layer. These aligners are fabricated using thermoforming techniques and are designed to provide improved force delivery and adaptability. Participants will wear the aligners intraorally for 10 days for at least 22 hours per day. Pre- and post-use evaluations will be conducted to assess mechanical properties and surface morphology changes. | Device | Triple-Layer TPU Aligner Group |
Primary outcome
Effect of Oral Environment on Elastic Modulus of TPU Aligners
Time frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
This outcome measures the change in elastic modulus (MPa) of thermoplastic polyurethane (TPU) orthodontic aligners following intraoral exposure. Measurements are obtained using a dynamic mechanical analyzer and compared between single-layer and multilayer TPU aligners at baseline and after two weeks of clinical use to assess changes in stiffness and material integrity.
Effect of Oral Environment on Stress Relaxation of TPU Aligners
Time frame: Time Frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
This outcome measures the percentage stress relaxation (%) of TPU aligners following intraoral exposure. Stress decay over time is recorded using a dynamic mechanical analyzer and compared between single-layer and multilayer TPU aligners at baseline and after two weeks to evaluate force retention capacity.
Effect of Oral Environment on Creep Behavior of TPU Aligners
Time frame: Time Frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)
This outcome measures creep (% strain) in TPU aligners under constant stress conditions using a dynamic mechanical analyzer. Comparisons are made between single-layer and multilayer TPU aligners at baseline and after two weeks to assess susceptibility to permanent deformation.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 May 2026.
Related trials for Malocclusion
Recruiting
FM Technique in Orthodontic Clear Aligner Therapy: A Single-Arm Clinical Study
Malocclusion
Not yet recruiting
Treatment of Mandibular Overjet in Children With Maxillary Retrognathism
Maxillary Retrognathism, Children
Active, not recruitingObservational study
Customized CBCT-Based Assessment of Transverse Discrepancies
Transverse Skeletal Discrepancy
Recruiting
Maxillary Arch Distalization With Infrazygomatic Crest Miniscrews for Class II Malocclusion
Class II Malocclusion
Enrolling by invitation
Evaluation of Corticotomy-Assisted Canine Retraction Rate
Malocclusion, Corticotomy
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Single-Layer Thermoplastic Polyurethane Aligner and Triple-Layer Thermoplastic Polyurethane Aligner in people with Malocclusion and Orthodontic Treatment, run by Ayub Medical College, Abbottabad at 1 site in Pakistan.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Pakistan. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Effect of Oral Environment on Elastic Modulus of TPU Aligners (time frame: Baseline (0 week) and after 2 weeks of intraoral use (minimum 22 hours/day)). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 May 2026.