Effect of varying thicknesses and temperature changes on shape memory behaviour in 3D DPA versus thermoformed clear aligner materials: An in vitro study - 03/10/25
, Praveen Kumar Varma Datla, Anoosha Manda, Sai Keerthi Velagala, Padma Priya CvHighlights |
• | Graphy introduced a new resin Tera Harz TA-28 for direct aligner printing, with claimed improvements in mechanical properties compared to TC-85. |
• | Shape recovery of TA-28 resin increased with temperature, while PET-G showed minimal recovery at all temperatures. |
• | TA-28 resin samples showed a geometry and thickness-dependant recovery behaviour. |
• | Type of the material, aligner thickness, and temperature changes significantly affected shape recovery. |
• | Direct 3D-printed TA-28 aligners offer consistent force delivery and improved predictability over thermoformed PET-G. |
Summary |
Background |
The present study evaluated the shape memory behaviour of TA-28 compared to PET-G at different thicknesses and temperatures.
Methods |
Two materials were tested: thermoformed CA Pro (PET-G) and 3D-printed TA-28 (Graphy, Korea), in 0.5mm and 0.75mm thicknesses. A total of 160 aligner strips were fabricated and tested for shape recovery at 30°C, 37°C, 40°C, and 80°C. Each strip was bent at 100°C and recovery was measured over 60minutes using a protractor-based template.
Results |
TA-28 exhibited significantly higher shape recovery than PET-G at all temperatures (P≤0.001). Recovery increased with temperature and was greatest for the 0.5mm TA-28 samples. At 37°C, TA-28 reached up to 60.7% recovery within 60minutes, while PET-G showed negligible change. Three-way ANOVA revealed significant interactions among material, thickness, and temperature (P=0.005).
Conclusion |
TA-28 aligners demonstrate superior shape memory properties compared to PET-G, particularly at body temperature. TA-28 samples with 0.5mm thickness recovered faster and to a greater extent, offering more consistent force delivery.
Clinical significance |
Directly 3D-printed TA-28 aligners may enhance treatment predictability, reduce patient discomfort, and provide sustained orthodontic force due to their temperature-responsive shape recovery. These findings support the use of smart materials in future orthodontic aligner design.
Le texte complet de cet article est disponible en PDF.Keywords : Clear aligners, Shape memory polymers, 3D printing, Thermoformed PET-G, Aligner thickness
Plan
Vol 24 - N° 1
Article 101073- mars 2026 Retour au numéro
Article précédent
- Effect of variations in mini-screw diameter, length, tapering, and thread depth on stress-strain distribution and displacement in alveolar bone: A three-dimensional finite element analysis
- Hamed Rahimi, Salva Khosroshahian, Faham Vjihi
- Patient-reported outcome measures of accelerated upper canine retraction with low-amperage electrical stimulation: A randomized controlled trial
- Mohammad N. Kheshfeh, Mohammad Y. Hajeer, Mohammad Khursheed Alam, Mhd Firas Al Hinnawi, Youssef Latifeh
Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Déjà abonné à cette revue ?