Original scientific paper
https://doi.org/10.15644/asc57/4/1
Differential Stability of One-layer and Three-layer Orthodontic Aligner Blends under Thermocycling: Implications for Clinical Durability
Luka Šimunović
; Department of Orthodontics, School of Dental Medicine, University of Zagreb, Gundulićeva 5, 10000 Zagreb, Croatia
Antonija Jurela
; Polyclinic Fiziodent, Turinina 5, 10000 Zagreb, Croatia
Karlo Sudarević
; Polyclinic Fiziodent, Turinina 5, 10000 Zagreb, Croatia
Ivana Bačić
; Forensic Science Centre “Ivan Vučetić”, Ministry of the Interior, Ilica 351, 10000 Zagreb, Croatia
Senka Meštrović
orcid.org/0000-0003-3224-3579
; Department of Orthodontics, School of Dental Medicine, University of Zagreb, Gundulićeva 5, 10000 Zagreb, Croatia
Abstract
Objectives: To optimize the therapeutic usefulness of aligners, it is crucial to understand how their mechanical properties alter with time. Materials and methods: Specimens from four different brands, including Duran+, CA® Pro, Zendura A, and Zendura FLX, were produced for material testing of thermoplastic orthodontic aligners (TOA) using dimensions measuring 4mm x 10mm. Each brand’s 24 samples were split into three groups as follows: G1 being thermoformed, G2 being thermoformed and underwent 500 thermocycles (simulating 7 days), and G3 being thermoformed and underwent 1000 thermocycles (simulating 14 days). Surface roughness, modulus of elasticity in bending, and spectrophotometry were used to assess the effect of aging on TOAs. Results: After 1000 thermocycles, Duran+ had the highest modulus of elasticity and differed statistically from all other groups. The intragroup comparison showed that only Duran+’s elastic modulus significantly changed after 1000 thermocycles in comparison with the control group. Surface roughness values (Ra), did not statistically differ among brands or thermocycling group measures. The change in chemical properties was not significant in any brand. Conclusion: One-layer PETG (Duran+) failed to demonstrate stability after in vitro aging, thus suggesting that clinicians should be aware of the change in mechanical properties when using one-layer PETG (Duran +) in a 2 weeks regime.
Keywords
Orthodontic Appliances; Materials Testing; Mechanical Tests; Aligners; Mechanical properties; Chemistry
Hrčak ID:
311905
URI
Publication date:
27.12.2023.
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