Investigation of the Mechanical Properties of Different Clear Aligner Materials

Yıl 2022, Sayı: 18, 1028 - 1040, 31.12.2022

Ayşegül Ural Özay , Gülnaz Marşan , Bülent Aydemir

https://doi.org/10.38079/igusabder.1125164

Öz

Aim: In order for the clear aligner treatment to be successful, the aligner material must provide sufficient orthodontic force to make the desired tooth movements without damaging the surrounding periodontal tissues. It is known that the mechanical properties of the material of the clear aligners have a critical role in the orthodontic force produced. In this study, it is aimed to determine the changes in the mechanical properties of different aligner materials that may affect the orthodontic force and to examine their effects.

Method: In this study, tensile tests were performed in accordance with the relevant standards in order to determine the mechanical properties of 6 different clear aligner materials (CA Pro, GT Flex, Zendura Flex, Zendura, Taglus, GT Pro). From the tensile test results, the parameters of the elastic modulus, tensile strength and elongation at break were obtained, as well as the stress-strain curves of the materials. The results were statistically evaluated and the mechanical properties of the materials were interpreted.

Results: According to material types, elastic modulus, tensile strength and elongation at break measurements showed statistically significant differences (p=0.001; p<0.01). When the paired comparisons were evaluated, it was determined that the Zendura Flex material had the lowest elastic modulus and tensile strength value, which was statistically significant.

Conclusion: According to the results of this study, the multilayered Zendura Flex and CA Pro materials showed the lowest elastic modulus and the lowest tensile strength values to support this result. The results of this study supported that different clear aligner materials show different mechanical properties. In order to increase the success of clear aligner treatment, it has been predicted that proper aligner materials can be determined with a good knowledge of the mechanical properties of aligner materials.

Anahtar Kelimeler

Clear aligners, mechanical properties, elastic modulus, Ortodonti, poliüretanlar, esneklik

Farklı Şeffaf Plak Materyallerinin Mekanik Özelliklerinin Araştırılması

Öz

Amaç: Şeffaf plak tedavisinin başarılı olabilmesi için, plak materyalinin çevre periodontal dokulara zarar vermeden istenilen diş hareketlerini yaptırabilecek yeterli ortodontik kuvveti sağlaması gerekmektedir. Şeffaf plakların malzemesinin mekanik özellikleri üretilen ortodontik kuvvet için kritik bir role sahip olduğu bilinmektedir. Bu çalışmada, farklı şeffaf plak materyallerinin ortodontik kuvveti etkileyebilecek mekanik özelliklerinin değişimlerinin tespiti ve etkilerinin incelenmesi amaçlanmıştır. Bu çalışmanın sıfır hipotezi, termoplastik malzemelerden elde edilmiş farklı şeffaf plak materyallerinin farklı mekanik özellikler göstermesi sebebiyle CA Pro, GT Flex, Zendura Flex, Zendura, Taglus ve GT Pro plak materyallerinin mekanik özelliklerinin incelenmesidir.

Yöntem: Çalışmada 6 farklı şeffaf plak materyalinin (CA Pro, GT Flex, Zendura Flex, Zendura, Taglus, GT Pro) mekanik özelliklerini belirlemek amacıyla ilgili standartlara uygun olarak çekme deneyleri yapılmıştır. Çekme deneyi sonuçlarından materyellerin gerilme uzama eğrilerinin yanında elastisite modülü, çekme dayanımı ve kopma uzaması parametreleri elde edilmiştir. Sonuçlar istastiksel olarak değerlendirilmiş ve materyallerin mekanik özellikleri yorumlanmıştır.

Bulgular: Materyal türlerine göre elastisite modülü, çekme dayanımı ve kopma uzaması ölçümleri istatistiksel olarak anlamlı farklılık göstermiştir (p=0,001; p<0,01). Yapılan ikili karşılaştırmalar değerlendirildiğinde en düşük elastisite modülü ve çekme dayanımı değerine Zendura Flex materyalinin sahip olmasının istatistiksel olarak anlamlı olduğu tespit edilmiştir.

Sonuç: Çalışmanın sonuçlarına göre çok katmanlı yapıda olan Zendura Flex ve CA Pro materyalleri, en düşük elastisite modülü ve bu sonucu destekleyecek şekilde en düşük çekme dayanımı değerleri göstermiştir. Çalışmanın sonuçları farklı şeffaf plak materyallerinin farklı mekanik özellikler gösterdiğini desteklemiştir. Şeffaf plak tedavisinin başarısını arttırmak amacıyla plak materyalleri mekanik özelliklerinin iyi bilinmesi ile uygun plak materyallerinin belirlenebileceği öngörülmüştür.

Anahtar Kelimeler

Ortodonti, poliüretanlar, esneklik

Kaynakça

• Weir T. Clear Aligners in Orthodontic Treatment. Aust Dent J. 2017;3(1):58-62. doi:10.1111/adj.12480.
• Karkhanechi M, Chow D, Sipkin J, et al. Periodontal status of adult patients treated with fixed buccal appliances and removable aligners over one year of active orthodontic theraphy. Angle Orthod. 2013;83(1):146-51. doi:10.2319/031212-217.1.
• Malik OH, McMullin A, Waring DT. Invisible orthodontics part 1: Invisalign. Dent Update. 2013;40(3):203-4. doi:10.12968/denu.2013.40.3.203.
• Graber TM. Clear Aligner Treatment. In: Paquette D, Colville C, Wheeler T, eds. Orthodontics: Current Principles and Techniques. St. Louis, Mosby; 2012:778-811.
• Fujiyama K, Honjo T, Suzuki M, Matsuoka S, Deguchi T. Analysis of pain level in cases treated with Invisalign aligner: Comparison with fixed edgewise appliance therapy. Prog Orthod. 2014;15(1):64. doi:10.1186/s40510-014-0064-7.
• Miller KB, McGorray SP, Womack R, et al. A comparison of treatment impacts between invisalign aligner and fixed appliance therapy during the first week of treatment. Am J Orthod Dentofacial Orthop. 2007;131(3):302.e1-9. doi:10.1016/j.ajodo.2006.05.031.
• Ali SA, Miethke HR. Invisalign, an innovative invisible orthodontic appliance to correct malocclusions: Advantages and limitations. Dent Update. 2012;39(4):254-6,258-60. doi:10.12968/denu.2012.39.4.254.
• Joffe L. Invisalign: Early experiences. J Orthod. 2003;30(4):348-52. doi:10.1093/ortho/30.4.348
• Drake C, McGorray S, Dolce C, Nair M, Wheeler T. Orthodontic tooth movement with clear aligners. ISRN Dent. 2012;2012:657973. doi:10.5402/2012/657973.
• Phan X, Ling PH. Clinical limitations of invisalign. Journal of the Canadian Dental Association. 2007;73(3):263-6.
• Benson H Wong. Invisalign a to z. American Journal of Orthodontics and Dentofacial Orthopedics. 2002;121(5):540-1. doi:10.1067/mod.2002.123036.
• Grossman W, Moss JP. Removable appliance therapy. JPO J Pract Orthod. 1968;2(1):28-36.
• Kesling HD. The philosophy of the tooth positioning appliance. Am J Orthod. 1945;31:297-304. doi:10.1016/0096-6347(45)90101-3
• Papadimitriou A, Mousoulea S, Gkantidis N, Kloukos D. Clinical effectiveness of invisalign orthodontic treatment: A systematic review. Prog Orthod. 2018;19(1):37. doi:10.1186/s40510-018-0235-z.
• Eliades T, Eliades G, Watts DC. Structural conformation of in vitro and in vivo aged orthodontic elastomeric modules. EurJ Orthod. 1999;21(6):649–58. doi: 10.1093/ejo/21.6.649.
• Johal A, Bondemark L. Clear aligner orthodontic treatment: Angle society of europe consensus viewpoint. J Orthod. 2021;48(3):300-304. doi:10.1177/14653125211006423.
• Lu H, Tang H, Zhou T, Kang N. Assessment of the periodontal health status in patients undergoing orthodontic treatment with fixed appliances and invisalign system: A meta- analysis. Medicine (Baltimore). 2018;97(13):e0248. doi:10.1097/MD.0000000000010248.
• Cervinara F, Cianci C, De Cillis F, et al. Experimental study of the pressures and points of application of the forces exerted between aligner and tooth. Nanomaterials. 2019;9:1010-8. doi:10.3390/nano9071010.
• Kohda N, Iijima M, Muguruma T, Brantley WA, Ahluwalia KS, Mizoguchi I. Effects of mechanical properties of thermoplastic materials on the initial force of thermoplastic appliances. Angle Orthod. 2013;83(3):476-83. doi:10.2319/052512-432.1.
• Savignano R, Viecilli RF, Paoli A, Razionale A, Barone S. Nonlinear dependency of tooth movement on force system directions. Am J Orthod Dentofacial Orthop. 2016;149(6):838-46. doi:10.1016/j.ajodo.2015.11.025.
• Alexandropoulos A, Al Jabbari YS, Zinelis S, Eliades T. Chemical and mechanical characteristics of contemporary thermoplastic orthodontic materials. Aust Orthod J. 2015;31(2):165-70. doi:10.21307/aoj-2020-151.
• Standardization IOf. ISO 527-1:2012 Plastics-Determination of Tensile Properties-Part 1: General principles. ISO. https://www.iso.org/standard/56045.html. Yayınlanma tarihi Şubat 2012. Güncellenme tarihi Temmuz 2019.
• Ma YS, Fang DY, Zhang N, Ding XJ, Zhang KY, Bai YX. Mechanical properties of orthodontic thermoplastics PETG/ PC2858 after blending. Chin J Dent Res. 2016;19(1):43-8. doi:10.3290/j.cjdr.a35696.
• Kwon JS, Lee YK, Lim BS, Lim YK. Force delivery properties of thermoplastic orthodontic materials. Am J Orthod Dentofacial Orthop. 2008;133(2):228-34. doi:10.1016/j.ajodo.2006.03.034.
• Beers A, Duong T. In: Tuncay OC, ed. Mechanics of Tooth Movement with Invisalign. New Malden, United Kingdom: Quintessence Publishing Company; 2006:149-151 Chapter 17.
• Sayuri I, Satoshi Y, Hiroshi U, Takashi Y, Satoshi I. Influence of constant strain on the elasticity of thermoplastic orthodontic materials. Dental Materials Journal. 2020;39(3):415-421. doi:10.4012/dmj.2019-104.
• Ryokawa H, Miyazaki Y, Fujishima A, Miyazaki T, Maki K. The mechanical properties of dental thermoplastic materials in a simulated intraoral environment. Orthod Waves. 2006;65:64-72. doi:10.1016/j.odw.2006.03.003.
• Tamburrino F, D'Antò V, Bucci R, Alessandri-Bonetti G, Barone S, Razionale AV. Mechanical properties of thermoplastic polymers for aligner manufacturing: In vitro study. Dent J (Basel). 2020;8(2):47-56. doi:10.3390/dj8020047.
• Nguyen AT. Quantitative Evaluation Criteria for the Mechanical Properties of Orthodontic Clear Aligners [master’s thesis]. Los Angeles, ABD: Science in Oral Biology, University of California; 2020.
• Keller, KJ. Stress Relaxation in Orthodontic Aligner Plastics; An In Vitro Comparison Study [thesis]. Omaha, ABD: Medical Sciences Interdepartmental Area, University of Nebraska Medical Center; 2020.