To compare the effects of mechanical properties on three different thermoplastic materials of different composition with same thickness for thermoformed orthodontic aligners

Background: Thermoformed orthodontic aligners are widely used in orthodontic treatment due to their aesthetic appeal and functional advantages.The mechanical properties of the thermoplastic materials used in aligners significantly influence their effectiveness in tooth movement.This study aims to compare the mechanical properties of three different thermoplastic materials-PET-G, CA PRO+, and UNIQ+ PD-of the same thickness, to determine their suitability for orthodontic aligners. Materials and Methods:An in-vitro experimental study was conducted to evaluate and compare the tensile strength, compressive strength, and flexural modulus of PET-G, CA PRO+, and UNIQ+ PD materials.A total of 21 specimens per material were prepared using a standardized thermoforming process.Mechanical tests, including tensile, compressive, and three-point bending tests, were performed.Data were analyzed using ANOVA to assess statistical significance.Results: The study revealed significant differences in the mechanical properties of the three tested materials.PET-G exhibited high tensile strength but showed susceptibility to micro-cracking.CA PRO+ demonstrated superior flexibility and resistance to deformation, making it a promising alternative for aligners requiring sustained force application.UNIQ+ PD exhibited excellent crack resistance and optical clarity, suggesting its potential for long-term aligner use.Statistical analysis confirmed significant variations in mechanical behavior among the tested materials.Conclusion: The mechanical properties of thermoformed orthodontic aligners vary based on material composition.While PET-G remains a commonly used material, CA PRO+ and UNIQ+ PD offer advantages in flexibility, crack resistance, and force retention.The findings of this study provide valuable insights into the selection of optimal aligner materials to enhance treatment outcomes.