The goal of this randomized clinical trial is to compare the accuracy of tooth movement achieved by 3D printed aligners versus thermoformed aligners in patients with lower anterior crowding. The study aims to evaluate whether directly printed aligners provide more accurate and predictable orthodontic tooth movement compared to conventional thermoformed aligners.

Recently, a new resin for 3D direct printed aligners (DPA) has been introduced. This resin, characterized by its viscoelastic properties, allows for precise control over material dimensions, structure, and properties. This enables the aligners to exert constant and gradual forces within the physiological limits of tooth movements .

Tera Harz Tc-58, a new direct-printed resin material introduced by Graphy Company, exhibits a significant shape memory effect. Approximately 90% of the deformation is recovered within 10 minutes, while 96% recovered after 60 minutes, whereas PETG maintains its deformed shape and shows no shape recovery.

DPA shows a significant enhancement in treating different moderate malocclusion cases by reducing the peer assessment rating (PAR) score by 86% and also reducing the need for attachment which simplifies treatment.

This study aims to determine the accuracy of DPA in facilitating tooth movement and to identify which types of tooth movements are more accurately achieved with DPA compared to conventional aligners.

Inclusion Criteria:

• Non-extraction orthodontic treatment cases
• Mild to moderate lower anterior crowding (<5 mm)
• Age between 12 and 25 years
• Dental rotation less than 30 degrees
• Relapse cases with crowding less than 5 mm

Exclusion Criteria:

• Active or history of periodontal disease
• Presence of systemic disease
• Temporomandibular joint disorders (TMJ)
• Missing teeth

The plan for sharing individual participant data is currently under consideration. Any data sharing will comply with institutional policies and participant confidentiality requirements.