Clinical Performance of Direct-Printed Versus Thermoformed Aligners

Official title

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

Overview

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.

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.

Interventions

• 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).
• 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.

Primary outcome measures

• Angular tooth movement tracking accuracy [Time frame: 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.]

Secondary outcome measures (6)

• Clinical efficiency [Time frame: 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.]
• Shape memory property [Time frame: 3 months]
• Color stability assessment [Time frame: 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.]
• Patient-Reported Treatment Discomfort [Time frame: The expected duration of subject participation from enrollment to the end of treatment is 6-12 months.]

Eligibility criteria

Inclusion criteria

• 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.
• Angle Class I non-extraction cases, presented with mild crowding or spacing (<5 mm) and dental rotation <30° .
• Good oral hygiene; no active caries/periodontal disease, no history of trauma or root resorption.

Exclusion criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Double blind

Primary purpose

Treatment

Study locations

Iraq · 3 centers

• Specialized Dental Center for Prosthodontics and Orthodontics — Baghdad
• Z Orchida Clinic — Baghdad
• Orthodontic department, College of dentistry, university of Baghdad. — Baghdad

Identifiers

NCT: NCT07637227 · 1197426

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗