Comparison of Dimensional Accuracy and Color Stability Between Direct 3D-printed and Thermoformed Retainers

NCT07053410 | Not Yet Recruiting

• 1 other identifier: Orthodontic retainers
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to compare two types of orthodontic retainers used after active treatment to maintain teeth position. The retainers are fabricated using either direct 3D-printing or thermoforming methods. The study will evaluate which method provides better dimensional accuracy (fit) and color stability over time. Adult patients who have completed their orthodontic treatment will be randomly assigned to one of three groups, each receiving a different type of retainer. The research is conducted at the Faculty of Dental Medicine, Al-Azhar University - Assiut Branch. The goal is to help orthodontists select the most reliable and durable type of retainer for long-term use.

Conditions

Orthodontic Retention Appliance; Clear Orthodontic Retainers

Keywords

Direct 3D-printed retainers; Multilayer retainer; Singlelayer retainer

Outcome Measures

Primary Outcomes (1)

• Mean Surface Deviation (mm) Between Retainer STL and Original STL Reference Model Assessed by 3D Superimposition After 1 Month

  Dimensional accuracy will be assessed by scanning each retainer and generating an STL file. The resulting STL will be superimposed on the original digital reference STL model using best-fit alignment in 3D inspection software (e.g., Geomagic Control X). The software will calculate the mean surface deviation in millimeters (mm). Results will be reported as mean ± standard deviation for each group (3D-printed vs thermoformed).

  1 month after retainer delivery

Secondary Outcomes (1)

• Color Change (ΔE) of Retainers Measured by Spectrophotometer Based on CIE L*a*b* System After 1 Month

  1 month after retainer delivery

Study Arms (3)

T1 - 3D-Printed Retainers

EXPERIMENTAL

Participants in this group will receive retainers fabricated using direct 3D printing technology with bio-compatible clear resin.

Device: Direct 3D-Printed Retainer

T2 - Single-Layer Thermoformed Retainers

ACTIVE COMPARATOR

Retainers fabricated using thermoplastic sheets and a standard thermoforming machine.

Device: Single-Layer Thermoformed Retainer

T3 - Multi-Layer Thermoformed Retainers

ACTIVE COMPARATOR

Participants in this group will receive retainers fabricated using a multi-layer thermoforming method

Device: Multi-Layer Thermoformed Retainer

Interventions

Direct 3D-Printed Retainer DEVICE

Orthodontic retainers fabricated using direct 3D printing technology from digital STL models. The retainers are printed with biocompatible clear resin using an additive manufacturing process.

T1 - 3D-Printed Retainers

Single-Layer Thermoformed Retainer DEVICE

Clear orthodontic retainers fabricated by thermoforming a single-layer thermoplastic sheet over a 3D printed dental model using a vacuum forming machine.

T2 - Single-Layer Thermoformed Retainers

Multi-Layer Thermoformed Retainer DEVICE

Orthodontic retainers fabricated using a multi-layer thermoforming technique combining different thermoplastic materials to enhance durability and fit accuracy.

T3 - Multi-Layer Thermoformed Retainers

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients who have completed their active orthodontic treatment.
• Adults aged 18 years and above.
• Cooperative individuals willing to participate.
• Patients with good oral hygiene and general health.
• No systemic diseases that may affect treatment outcomes.

You may not qualify if:

• Smokers.
• Patients with a history of poor compliance with previous orthodontic treatment.
• Patients with parafunctional oral habits (e.g., bruxism).
• Patients undergoing retreatment due to relapse.

Sponsors & Collaborators

• Essraa hassan Hussein Mohamed: lead

Study Sites (1)

Faculty of Dental Medicine, Al-Azhar University - Assiut Branch

Asyut, Assuit, 71511, Egypt

Location

Study Officials

• Mostafa M. Dawaba, PhD

  Faculty of Dental Medicine, Al-Azhar University - Assiut Branch

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Essraa H. Mohammed

CONTACT

00201159327869; Essraa_elaraby88@yahoo.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Master's Degree Candidate in Orthodontics

Model Details: Participants will be randomly assigned to one of three parallel arms: 3D-printed retainers, single-layer thermoformed retainers, or multi-layer thermoformed retainers.

Study Record Dates

• First Submitted: June 18, 2025
• First Posted: July 8, 2025
• Study Start: July 1, 2025
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): December 1, 2028
• Last Updated: July 11, 2025

Record last verified: 2025-07

Data Sharing

• IPD Sharing: Will not share

Locations

EG (1)