Comparison of Force Delivery Profiles Between Thermoformed Aligners and Direct Printed Aligners During Canine Rotation: An In vitro Study
DOI:
https://doi.org/10.65795/vkxn9g80Keywords:
clear aligners, thermoformed aligners, 3D printed aligners, force delivery, aging, orthodonticAbstract
Clear aligner therapy has become increasingly popular owing to its aesthetic and functional benefits; however, the force delivery characteristics of various aligner materials are not well understood. The advent of direct 3D-printed aligners has necessitated their comparison with traditional thermoformed materials. This study aimed to evaluate the force delivery of thermoformed (Zendura Viva) and direct 3D-printed (TA28) clear aligners during 1° and 2° rotational tooth movements, both before and after artificial aging. A total of 24 aligners were produced and categorized into two primary groups based on the material: thermoformed (Zendura Viva) and direct 3D-printed (TA28). Each group was further divided into subgroups for 1° and 2° rotational activation (n = 6 per subgroup). Force measurements were obtained using an FSR402 sensor integrated with an Arduino-based system under standardized conditions before (T0) and after artificial aging (T1), which involved thermocycling and incubation in artificial saliva. The initial force values of the thermoformed aligners were significantly higher than those of the direct 3D-printed aligners (p < 0.001). Artificial aging led to a notable reduction in force for both materials across all groups (P < 0.001). The three-way ANOVA revealed significant effects of material and aging, as well as a significant interaction between material and aging (p < 0.001), whereas the degree of rotation did not have a significant independent effect (p > 0.05). After aging, no statistically significant differences were observed between the materials. Thermoformed aligners provide higher initial forces; however, both thermoformed and direct 3D-printed aligners experience significant force degradation after aging, resulting in similar residual force levels. The degree of rotational activation has a limited impact on the long-term force delivery. These findings underscore the importance of material selection and force sustainability in optimizing orthodontic treatment using clear aligners.
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References
Tamer I, Oztas E, Marsan G. Orthodontic Treatment with Clear Aligners and The Scientific Reality Behind Their Marketing: A Literature Review. Turk J Orthod. 2019;32(4):241-246. doi:10.5152/turkjorthod.2019.18083 DOI: https://doi.org/10.5152/TurkJOrthod.2019.18083
Almogbel A. Clear Aligner Therapy: Up to date review article. J Orthodont Sci. 2023;12(1):37. doi:10.4103/jos.jos_30_23 DOI: https://doi.org/10.4103/jos.jos_30_23
Niu C, Li D, Zhang Y, et al. Prospects for 3D-printing of clear aligners: a narrative review. Front Mater. 2024;11. doi:10.3389/fmats.2024.1438660 DOI: https://doi.org/10.3389/fmats.2024.1438660
Tartaglia GM, Mapelli A, Maspero C, et al. Direct 3D Printing of Clear Orthodontic Aligners: Current State and Future Possibilities. Materials. 2021;14(7):1799. doi:10.3390/ma14071799 DOI: https://doi.org/10.3390/ma14071799
Li N, Wang C, Yang M, et al. Effects of different tooth movement patterns and aligner thicknesses on maxillary arch expansion with clear aligners: a three-dimensional finite element study. Front Bioeng Biotechnol. 2024;12. doi:10.3389/fbioe.2024.1424319 DOI: https://doi.org/10.3389/fbioe.2024.1424319
Bae BG, Kim YH, Lee GH, et al. A study on the compressive strength of three-dimensional direct printing aligner material for specific designing of clear aligners. Sci Rep. 2025;15(1). doi:10.1038/s41598-025-86687-4 DOI: https://doi.org/10.1038/s41598-025-86687-4
Rossini G, Schiaffino M, Parrini S, Sedran A, Deregibus A, Castroflorio T. Upper Second Molar Distalization with Clear Aligners: A Finite Element Study. Applied Sciences. 2020;10(21):7739. doi:10.3390/app10217739 DOI: https://doi.org/10.3390/app10217739
Sultanoğlu E, Gürel HG, Gülyurt M. The Effects of Different Attachment Types and Positions on Rotation Movement in Clear Aligner Treatments: A Finite Element Analysis. Cureus. 2024;16(8). doi:10.7759/cureus.66273 DOI: https://doi.org/10.7759/cureus.66273
Cortona A, Rossini G, Parrini S, Deregibus A, Castroflorio T. Clear aligner orthodontic therapy of rotated mandibular round-shaped teeth: A finite element study. The Angle Orthodontist. 2019;90(2):247-254. doi:10.2319/020719-86.1 DOI: https://doi.org/10.2319/020719-86.1
Pede K, Shetty P, Ranjan A, Khan W, Patil H, Mishra H. Evaluation of effects of different sizes and shapes of attachments during rotation, tipping, and torquing in clear aligner therapy - A finite element study. Journal of orthodontic science. 2024;13(1). doi:10.4103/jos.jos_199_23 DOI: https://doi.org/10.4103/jos.jos_199_23
Zamani NSM, Ashari A, Ali SHM, et al. Distributed Force Measurement and Mapping Using Pressure-Sensitive Film and Image Processing for Active and Passive Aligners on Orthodontic Attachments. IEEE Access. 2022;10:52853-52865. doi:10.1109/access.2022.3175210 DOI: https://doi.org/10.1109/ACCESS.2022.3175210
Alhafi ZM, Hajeer MY, Alam MK, Jaber ST. Quality and stability of orthodontic treatment outcomes with clear aligners versus fixed appliances: a systematic review and meta-analysis. European journal of orthodontics. 2025;47(6). doi:10.1093/ejo/cjaf091 DOI: https://doi.org/10.1093/ejo/cjaf091
Cenzato N, Di Iasio G, Martìn Carreras-Presas C, Caprioglio A, Del Fabbro M. Materials for Clear Aligners—A Comprehensive Exploration of Characteristics and Innovations: A Scoping Review. Applied Sciences. 2024;14(15):6533. doi:10.3390/app14156533 DOI: https://doi.org/10.3390/app14156533
Barone S, Paoli A, Neri P, Razionale AV, Giannese M. Mechanical and Geometrical Properties Assessment of Thermoplastic Materials for Biomedical Application. In: Springer; 2016:437-446. doi:10.1007/978-3-319-45781-9_44 DOI: https://doi.org/10.1007/978-3-319-45781-9_44
Szczesio-Wlodarczyk A, Fronczek M, Ranoszek-Soliwoda K, Grobelny J, Sokolowski J, Bociong K. The First Step in Standardizing an Artificial Aging Protocol for Dental Composites—Evaluation of Basic Protocols. Molecules. 2022;27(11):3511. doi:10.3390/molecules27113511 DOI: https://doi.org/10.3390/molecules27113511
Kuntz L, Aranda L, Rapin C, Canceill T, Vande Vannet B, Fawaz P. Effects of aging on the tensile strength and surface condition of orthodontic aligners: a comparative study of five models. European journal of orthodontics. 2024;46(6). doi:10.1093/ejo/cjae063 DOI: https://doi.org/10.1093/ejo/cjae063
Siotou K, Chountalas T, Katsavrias A, et al. The Mechanical Properties of Orthodontic Aligners of Clear Aligner After Intraoral Use in Different Time Periods. Orthod Craniofacial Res. 2024;28(2). doi:10.1111/ocr.12867 DOI: https://doi.org/10.1111/ocr.12867
Bleilöb M, Welte-Jzyk C, Knode V, Ludwig B, Erbe C. Biocompatibility of variable thicknesses of a novel directly printed aligner in orthodontics. Sci Rep. 2025;15(1). doi:10.1038/s41598-025-85359-7 DOI: https://doi.org/10.1038/s41598-025-85359-7
Choi JY, Kim H, Kim SH, et al. Mechanical and viscoelastic properties of a temperature-responsive photocurable resin for 3D printed orthodontic clear aligners. Sci Rep. 2025;15(1). doi:10.1038/s41598-025-93026-0 DOI: https://doi.org/10.1038/s41598-025-93026-0
Elshazly TM, Bourauel C, Ismail AM, et al. Effect of thermomechanical ageing on force transmission by orthodontic aligners made of different thermoformed materials: An experimental study. Orthod Craniofacial Res. 2024;Suppl 27 2(S2):113-119. doi:10.1111/ocr.12825 DOI: https://doi.org/10.1111/ocr.12825
Golkhani B, Weber A, Keilig L, Reimann S, Bourauel C. Variation of the modulus of elasticity of aligner foil sheet materials due to thermoforming. J Orofac Orthop. 2021;83(4):233-243. doi:10.1007/s00056-021-00327-w DOI: https://doi.org/10.1007/s00056-021-00327-w
El Idrissi I, El Mabrouk K, Zaoui F, Benyahia H. Performance of orthodontic aligners in the aging process: systematic review and in vitro study. l Orthodontie Française. 2021;92(3):335-341. doi:10.1684/orthodfr.2021.57 DOI: https://doi.org/10.1684/orthodfr.2021.57
Diedrich P. Biomechanical principles of orthodontic movement of teeth with periodontal involvement. Deutsche zahnärztliche Zeitschrift. 1990;45(2):78-81.
Ren Y, Maltha J, Kuijpers-Jagtman AM. Optimum force magnitude for orthodontic tooth movement: a systematic literature review. The Angle orthodontist. 2015;73(1):86-92. doi:10.1043/0003-3219(2003)073<0086:ofmfot>2.0.co;2
Simon M, Keilig L, Schwarze J, Jung BA, Bourauel C. Forces and moments generated by removable thermoplastic aligners: Incisor torque, premolar derotation, and molar distalization. American Journal of Orthodontics and Dentofacial Orthopedics. 2014;145(6):728-736. doi:10.1016/j.ajodo.2014.03.015 DOI: https://doi.org/10.1016/j.ajodo.2014.03.015
Cremonini F, Pancari C, Brucculeri L, Karami Shabankare A, Lombardo L. Force Expressed by 3D-Printed Aligners with Different Thickness and Design Compared to Thermoformed Aligners: An in Vitro Study. Applied Sciences. 2025;15(6):2911. doi:10.3390/app15062911 DOI: https://doi.org/10.3390/app15062911
Gornig DC, Maletz R, Ottl P, Warkentin M. Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression. Clin Oral Invest. 2021;26(2):1491-1504. doi:10.1007/s00784-021-04122-0 DOI: https://doi.org/10.1007/s00784-021-04122-0
Ryu JH, Kwon JS, Jiang HB, Cha JY, Kim KM. Effects of thermoforming on the physical and mechanical properties of thermoplastic materials for transparent orthodontic aligners. Korean J Orthod. 2018;48(5):316. doi:10.4041/kjod.2018.48.5.316 DOI: https://doi.org/10.4041/kjod.2018.48.5.316
Atta I, Bourauel C, Alkabani Y, et al. Physiochemical and mechanical characterisation of orthodontic 3D printed aligner material made of shape memory polymers (4D aligner material). Journal of the Mechanical Behavior of Biomedical Materials. 2023;150:106337. doi:10.1016/j.jmbbm.2023.106337 DOI: https://doi.org/10.1016/j.jmbbm.2023.106337
Lombardo L, Martines E, Mazzanti V, Arreghini A, Mollica F, Siciliani G. Stress relaxation properties of four orthodontic aligner materials: A 24-hour in vitro study. The Angle Orthodontist. 2016;87(1):11-18. doi:10.2319/113015-813.1 DOI: https://doi.org/10.2319/113015-813.1
Mckay A, Mccray J, Bankhead B, et al. Forces and moments generated during extrusion of a maxillary central incisor with clear aligners: an in vitro study. BMC Oral Health. 2023;23(1). doi:10.1186/s12903-023-03136-2 DOI: https://doi.org/10.1186/s12903-023-03136-2
Sayahpour B, Zinelis S, Polychronis G, et al. Effects of intraoral aging on mechanical properties of directly printed aligners vs. thermoformed aligners: an in vivo prospective investigation. European Journal of Orthodontics. 2023;46(1). doi:10.1093/ejo/cjad063 DOI: https://doi.org/10.1093/ejo/cjad063
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Copyright (c) 2026 Mahalakshmi Krishnakumaran, Roshini T., Parameswaran T.M., Balaji Krishnan, Deepak Prabhu (Author)
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Accepted 13-07-2026
Published 30-07-2026
