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.
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.
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.
Parallel
Direct 3D-Printed Retainer
DeviceOrthodontic retainers fabricated using direct 3D printing technology from digital STL models. The retainers are printed with biocompatible clear resin using an additive manufacturing process.
Single-Layer Thermoformed Retainer
DeviceClear orthodontic retainers fabricated by thermoforming a single-layer thermoplastic sheet over a 3D printed dental model using a vacuum forming machine.
Multi-Layer Thermoformed Retainer
DeviceOrthodontic retainers fabricated using a multi-layer thermoforming technique combining different thermoplastic materials to enhance durability and fit accuracy.
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).
Color Change (ΔE) of Retainers Measured by Spectrophotometer Based on CIE L*a*b* System After 1 Month
Color 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.
Click on the lead sponsor to view all of their trials.
Essraa hassan Hussein Mohamed
Lead sponsor
Al-Azhar University
Sponsor institution
This trial is not recruiting at the moment. You can still explore other options:
