Clinical Performance of Direct-Printed Versus Thermoformed Aligners

June 5, 2026 updated by: Ali Rahman Issa, University of Baghdad

Clinical Performance of In-Office Directly Printed Versus Thermoformed Aligners: A Randomized Clinical Trial

The goal of this study is to evaluate and compare the clinical effectiveness of in-office directly 3D-printed clear aligners versus conventional multilayered thermoformed aligners.

The main question it aims to answer is:

Does the use of in-office direct-printed shape-memory aligners result in superior clinical effectiveness, compared to established multilayer thermoformed aligner systems?

Researchers will compare a Direct-Printed Aligner (DPA) group using Senertek Clear-A V2 resin to a Thermoformed Aligner (TFA) group using Zendura FLX multilayer sheets to see if the additive manufacturing process improves clinical outcomes and patient satisfaction.

Participants will:

  • Undergo initial records including intraoral digital scans, photos, and a panoramic radiograph for treatment planning.
  • Wear their assigned clear aligners (either direct-printed or thermoformed) for at least 22 hours per day, changing them every 7 days.
  • Attend follow-up appointments every 5 weeks.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a prospective, parallel-arm randomized controlled multi-center clinical trial, to assess and compare the clinical effectiveness of in-office 3D-printed clear aligners with multilayered thermoformed aligners.

The subject population for this study will be male and female subjects aged 16-30 years who have fully erupted permanent dentition and mild dental crowding or spacing.

Methodology:

Patients requiring orthodontic treatment are randomly allocated into two groups.

Experimental Group (DPA): Aligners are fabricated using additive manufacturing (direct 3D printing) with Senertek Clear-A V2 shape-memory resin. This process eliminates the intermediate physical model, potentially reducing cumulative manufacturing errors.

Control Group (TFA): Aligners are fabricated by thermoforming multilayered thermoplastic sheets (Zendura FLX) over 3D-printed resin molds.

Assessment:

Digital models (STL files) will be obtained at the start (T0) and at the end of the treatment (T1). These will be compared to the digital treatment plan (Tp) using 3D superimposition and trigonometric analysis. Stable anatomical structures, such as the palatal rugae, will serve as reference points for superimposition. The primary outcome is the "Tracking Accuracy Percentage," which measures how closely the actual clinical tooth movement matches the digitally predicted movement. Secondary outcomes include clinical efficiency, patient-reported pain levels, and Manufacturing complexity, including total fabrication time.

Study Type

Interventional

Enrollment (Estimated)

34

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Iraq
      • Baghdad, Iraq, 10013
      • Baghdad, Iraq, 10047
    • Bab Al-Muadham
      • Baghdad, Bab Al-Muadham, Iraq, 10047

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Adult patient with an age range of 15-30 with fully erupted all permanent dentitions excluding third molars, and a willingness to participate in the trial.
  2. Angle Class I non-extraction cases, presented with mild crowding or spacing (<5 mm) and dental rotation <30° .
  3. Good oral hygiene; no active caries/periodontal disease, no history of trauma or root resorption.

Exclusion Criteria:

  1. Pregnancy, smoking, and systemic conditions affecting bone remodeling.
  2. Subject with poor oral hygiene, using simplified oral hygiene index (OHI-S ≥ 3.1 ) (Greene & Vermillion, 1963).
  3. Patient with malposed lower second molars (need orthodontic alignment).
  4. Allergy to materials used (resins, plastics, solvents).
  5. History of trauma, root resorption, and dilacerated roots.
  6. Previous extraction or history of previous orthodontic treatment.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Direct-Printed Aligner
Participants in this group will receive clear aligners manufactured using in-office 3D printing technology. This arm tests the effectiveness of additive manufacturing and the shape-memory properties of the resin in achieving programmed tooth movements.
Device: Direct-Printed Aligner
Participants in this group will receive clear aligner therapy fabricated via direct-printing, utilizing a specialized light-curable resin (Clear-A V2, Senertek, İzmir, Turkey).
Active Comparator: Thermoformed Aligner
Participants in this group will receive conventional clear aligners manufactured using the vacuum-forming (thermoforming) process. This arm serves as the gold standard to which the experimental 3D-printed aligners are compared.
Device: Thermoformed aligner
Participants in this group will treated with clear aligners fabricated via the conventional indirect method, involving the thermoforming of thermoplastic sheets (Zendura FLX, Zendura dental, Fremont, California) over 3D-printed dental molds.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Angular tooth movement tracking accuracy
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Digital models (Initial (T0), planned (Tp), and final (T1)) will be compared using trigonometry. Angular measurements of vestibulo-lingual tipping, mesio-distal tipping, and rotation, will be performed on the three digital casts that had been previously superimposed.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Linear tooth movement tracking accuracy
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Evaluation of the tracking accuracy of linear tooth movements (in millimeters) by superimposing three-dimensional digital dental models across three therapeutic stages: Initial (T0), Planned (Tp), and Final (T1). Trigonometric spatial analysis will be executed on the superimposed digital casts to quantify the absolute positional discrepancy between the virtually planned tooth position and the actual clinically achieved position.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Clinical efficiency
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
The additional treatment time necessitated by refinements will be calculated and compared statistically between the study groups.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Evaluate degree of conversion
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
The relative concentration of unreacted aliphatic carbon double bonds will be evaluated by measuring the peak areas of the aliphatic C=C stretching vibrations (at 1634 cm -1 and 1620 cm-1) and the stable internal standard (N-H bending absorption at 1523 cm-1) via the tangent baseline technique. These distinct spectral values will be mathematically aggregated using the standard normalized ratio equation: DC (%)=[1-(R cured/R monomer)]×100. Unit of Measure, percentage (%) of converted double bonds.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Shape memory property
Time Frame: 3 months
The percentage of shape recovery over time and the total deformation angles exhibited by both the direct-printed resin (Senertek Clear-A V2) and the thermoformed aligner sheets.Quantitative measurements will be recorded using a standardized thermo-mechanical bending test layout under controlled temperature intervals.
3 months
Color stability assessment
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Optical transmittance will be measured across the visible light spectrum to evaluate and compare the transparency degradation and color stability of direct-printed versus thermoformed aligners before and after in vivo aging.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Manufacturing complexity and fabrication time
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
For each workflow, the total production time, hands-on labor, and material expenses will be recorded and analyzed.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Patient-Reported Treatment Discomfort
Time Frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.
Patient-reported pain or discomfort evaluated on a standard horizontal Visual Analogue Scale (VAS) ranging from 0 (no pain) to 100 (severe pain). Unit of Measure, millimeters (mm) on a 100 mm scale.
The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Baghdad

Investigators

  • Study Director: Noor Muhammed Garma, Assistant Professor, University of Baghdad, College of Dentistry, Department of Orthodontic.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

September 1, 2027

Study Completion (Estimated)

October 1, 2027

Study Registration Dates

First Submitted

May 23, 2026

First Submitted That Met QC Criteria

June 5, 2026

First Posted (Actual)

June 9, 2026

Study Record Updates

Last Update Posted (Actual)

June 9, 2026

Last Update Submitted That Met QC Criteria

June 5, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 1197426

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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