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

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.