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

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

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07053410
Enrollment
30
Registered
2025-07-08
Start date
2025-07-31
Completion date
2028-12-31
Last updated
2025-07-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Clear Orthodontic Retainers, Orthodontic Retention Appliance

Keywords

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

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.

Detailed description

This randomized clinical and laboratory study investigates the dimensional accuracy and color stability of orthodontic retainers fabricated using two different techniques: direct 3D printing and thermoforming. Patients who have completed active orthodontic treatment will be recruited and assigned to three groups. Group T1 will receive 3D-printed retainers, Group T2 will receive single-layer thermoformed retainers, and Group T3 will receive multi-layer thermoformed retainers…

Interventions

DEVICEDirect 3D-Printed Retainer

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.

DEVICESingle-Layer Thermoformed Retainer

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

DEVICEMulti-Layer Thermoformed Retainer

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

Sponsors

Essraa hassan Hussein Mohamed
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Intervention model description

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

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* 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.

Exclusion criteria

* 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.

Design outcomes

Primary

MeasureTime frameDescription
Mean Surface Deviation (mm) Between Retainer STL and Original STL Reference Model Assessed by 3D Superimposition After 1 Month1 month after retainer deliveryDimensional 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).

Secondary

MeasureTime frameDescription
Color Change (ΔE) of Retainers Measured by Spectrophotometer Based on CIE L*a*b* System After 1 Month1 month after retainer deliveryColor stability will be evaluated by measuring the color of each retainer before and after intraoral use using a spectrophotometer. The color change (ΔE) will be calculated according to the CIE L\*a\*b\* color system formula. Results will be reported as mean ΔE ± standard deviation for each group. A ΔE value \>3.3 will be considered visually perceptible.

Countries

Egypt

Contacts

Primary ContactEssraa H. Mohammed
Essraa_elaraby88@yahoo.com00201159327869

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026