Assessment of active memory of photo-curable resins for LuxCreo DCA direct-printed 3D aligners

Objectives: Direct 3D-printed aligners represent an innovative advancement in orthodontics, offering a promising alternative to traditional thermoformed aligners. These aligners are fabricated from photo-curable resins with unique shape memory properties, enabling the application of light, continuous forces that optimize tooth movement and treatment efficiency. This study evaluates the thermomechanical properties, shape memory characteristics, and force retention capabilities of two novel photo-curable polymers, direct printed clear aligner (DCA) and DCA Plus, for their suitability in orthodontic applications. Material and Methods: A series of thermomechanical and mechanical tests were conducted, including dynamic mechanical analysis to assess temperature-dependent modulus changes, shape memory evaluation to measure dimensional stability and recovery, and force restoration tests to quantify sustained orthodontic force application. Statistical analysis, including analysis of variance ( P < 0.05), was performed to determine significant differences in material performance. Results: The results indicate that DCA and DCA Plus exhibit high glass transition temperatures (Tg: 118°C and 130°C, respectively), excellent thermomechanical stability, and minimal force decay at intraoral temperatures (37°C). Shape memory tests showed that DCA Plus retained 95.8% of its original shape within ±0.05 mm tolerance and 99.4% within ±0.1 mm tolerance following thermal activation. Force restoration experiments demonstrated that after deformation, the material could fully recover its mechanical properties through simple thermal excitation, confirming its ability to provide consistent orthodontic force over time. Conclusion: These findings suggest that DCA and DCA Plus offer significant advantages over traditional thermoformed aligners, including superior shape retention, improved force sustainability, and reduced reliance on attachments. Their application in direct 3D printing could enhance treatment efficiency and patient compliance. Further independent research and clinical validation are indicated to confirm these advantages in orthodontic practice.