Biomechanical aging behaviour of clear aligners

Translucency Parameter					Roughness – internal surface (μm)				Roughness – external surface (μm)
		Lower	Upper			Lower	Upper			Lower	Upper
Day	Mean±SD	95% CI	95% CI	P-value	Mean±SD	95% CI	95% CI	P-value	Mean±SD	95% CI	95% CI	P-value
0	3.69 ± 0.66	2.05	5.34	P > 0.05	5.53 ± 0.26	4.89	6.17	P > 0.05	1.34 ± 0.04	1.23	1.44	P > 0.05
1	4.97 ± 3.32	-3.27	13.20	P > 0.05	5.30 ± 0.23	4.74	5.87	P > 0.05	1.53 ± 0.10	1.28	1.77	P > 0.05
2	4.31 ± 4.25	-6.24	14.86	P > 0.05	5.64 ± 0.8	3.65	7.64	P > 0.05	1.72 ± 0.06	1.58	1.87	P > 0.05
3	3.10 ± 1.84	-1.47	7.67	P > 0.05	5.65 ± 0.67	3.97	7.32	P > 0.05	1.44 ± 0.50	0.19	2.69	P > 0.05
4	4.93 ± 2.91	-2.30	12.17	P > 0.05	5.39 ± 0.41	4.37	6.4	P > 0.05	1.60 ± 0.54	0.27	2.93	P > 0.05
5	4.85 ± 0.91	2.58	7.12	P > 0.05	5.33 ± 0.58	3.9	6.77	P > 0.05	1.45 ± 0.30	0.7	2.2	P > 0.05
6	4.50 ± 1.59	0.54	8.46	P > 0.05	5.45 ± 0.49	4.24	6.65	P > 0.05	1.45 ± 0.25	0.84	2.07	P > 0.05
7	3.87 ± 0.75	2.01	5.73	P > 0.05	5.58 ± 0.21	5.05	6.1	P > 0.05	1.29 ± 0.19	0.82	1.75	P > 0.05
8	4.72 ± 0.35	3.86	5.59	P > 0.05	5.47 ± 0.49	4.25	6.68	P > 0.05	1.38 ± 0.50	0.14	2.62	P > 0.05
9	3.20 ± 1.59	-0.76	7.15	P > 0.05	5.27 ± 1.07	2.61	7.94	P > 0.05	1.48 ± 0.45	0.37	2.59	P > 0.05
10	2.35 ± 0.84	0.27	4.44	P > 0.05	5.23 ± 0.65	3.61	6.86	P > 0.05	1.65 ± 0.06	1.51	1.79	P > 0.05
11	3.89 ± 1.61	-0.11	7.89	P > 0.05	5.64 ± 0.03	5.55	5.73	P > 0.05	1.72 ± 0.05	1.59	1.85	P > 0.05
12	2.35 ± 0.19	1.86	2.83	P > 0.05	5.39 ± 0.19	4.92	5.87	P > 0.05	1.52 ± 0.13	1.2	1.84	P > 0.05
13	4.76 ± 1.43	1.20	8.32	P > 0.05	5.54 ± 0.08	5.33	5.74	P > 0.05	1.34 ± 0.51	0.07	2.61	P > 0.05
14	2.51 ± 1.06	-0.12	5.14	P > 0.05	5.45 ± 0.52	4.15	6.74	P > 0.05	1.55 ± 0.45	0.42	2.67	P > 0.05
15	2.53 ± 0.33	1.72	3.34	P > 0.05	5.80 ± 0.03	5.73	5.87	P > 0.05	1.27 ± 0.05	1.14	1.41	P > 0.05
16	3.62 ± 1.96	-1.24	8.49	P > 0.05	5.57 ± 0.52	4.27	6.86	P > 0.05	1.75 ± 0.25	1.14	2.36	P > 0.05
17	2.36 ± 0.39	1.40	3.32	P > 0.05	5.53 ± 0.19	5.07	6.00	P > 0.05	1.72 ± 0.10	1.46	1.98	P > 0.05
18	2.65 ± 1.30	-0.57	5.88	P > 0.05	5.78 ± 0.27	5.1	6.46	P > 0.05	1.63 ± 0.24	1.04	2.23	P > 0.05
19	5.97 ± 1.35	2.63	9.32	P > 0.05	5.41 ± 0.77	3.5	7.31	P > 0.05	1.81 ± 0.09	1.58	2.05	P > 0.05
20	3.75 ± 1.88	-0.91	8.41	P > 0.05	5.28 ± 0.78	3.34	7.21	P > 0.05	1.68 ± 0.18	1.23	2.14	P > 0.05
21	4.49 ± 0.75	2.64	6.34	P > 0.05	5.31 ± 0.78	3.36	7.25	P > 0.05	1.70 ± 0.25	1.07	2.32	P > 0.05

Surface roughness of the clear aligners was not significantly changed by the simulated aging process.

Table II.

Tensile strength and maximum load of the clear aligners did not change significantly during the 21-day study (P > 0.05 for all, n=3 in each group)

Tensile strength (N/mm²)					Maximum load (N/mm²)
		Lower	Upper			Lower	Upper
Day	Mean±SD	95% CI	95% CI	P-value	Mean±SD	95% CI	95% CI	P-value
0	20.85 ± 1.08	18.18	23.53	> 0.05	104.26 ± 5.38	18.18	23.53	> 0.05
1	20.55 ± 2.75	16.17	24.92	> 0.05	102.74 ± 13.75	16.17	24.92	> 0.05
2	21.38 ± 3.38	16.00	26.76	> 0.05	106.89 ± 16.91	16.00	26.76	> 0.05
3	19.87 ± 3.10	14.93	24.80	> 0.05	99.34 ± 15.50	14.93	24.80	> 0.05
4	20.28 ± 2.44	16.41	24.16	> 0.05	101.42 ± 12.18	16.41	24.16	> 0.05
5	20.98 ± 3.20	15.88	26.08	> 0.05	104.91 ± 16.02	15.88	26.08	> 0.05
6	20.01 ± 2.61	15.85	24.16	> 0.05	100.05 ± 13.06	15.85	24.16	> 0.05
7	19.02 ± 0.48	18.26	19.78	> 0.05	95.11 ± 2.39	18.26	19.78	> 0.05
8	21.70 ± 3.90	15.49	27.91	> 0.05	108.50 ± 19.51	15.49	27.91	> 0.05
9	20.11 ± 3.01	15.32	24.91	> 0.05	100.57 ± 15.06	15.32	24.91	> 0.05
10	18.98 ± 4.34	12.07	25.88	> 0.05	94.89 ± 21.69	12.07	25.88	> 0.05
11	22.02 ± 2.46	18.10	25.93	> 0.05	110.08 ± 12.30	18.10	25.93	> 0.05
12	18.22 ± 3.48	12.67	23.76	> 0.05	91.08 ± 17.42	12.67	23.76	> 0.05
13	18.95 ± 2.84	14.43	23.46	> 0.05	94.74 ± 14.18	14.43	23.46	> 0.05
14	18.82 ± 1.56	16.33	21.31	> 0.05	94.08 ± 7.82	16.33	21.31	> 0.05
15	21.11 ± 2.61	16.95	25.26	> 0.05	105.53 ± 13.05	16.95	25.26	> 0.05
16	20.43 ± 4.67	13.01	27.85	> 0.05	102.15 ± 23.33	13.01	27.85	> 0.05
17	19.45 ± 3.11	14.51	24.40	> 0.05	97.27 ± 15.53	14.51	24.40	> 0.05
18	18.93 ± 0.32	18.41	19.44	> 0.05	94.65 ± 1.62	18.41	19.44	> 0.05
19	21.08 ± 1.75	18.29	23.86	> 0.05	105.38 ± 8.75	18.29	23.86	> 0.05
20	18.40 ± 2.80	13.94	22.86	> 0.05	91.99 ± 14.01	13.94	22.86	> 0.05
21	17.63 ± 3.58	11.94	23.32	> 0.05	88.17 ± 17.88	11.94	23.32	> 0.05

Hardness of the clear aligners was significantly reduced after 10 days of the simulated aging process.

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DOI: https://doi.org/10.2478/aoj-2024-0006 | Journal eISSN: 2207-7480 | Journal ISSN: 2207-7472

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Language: English

Page range: 60 - 66

Submitted on: Dec 1, 2023

Accepted on: Feb 1, 2024

Published on: Mar 20, 2024

Published by: Australian Society of Orthodontists Inc.

In partnership with: Paradigm Publishing Services

Publication frequency: 1 issue per year

Related subjects:

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Basic medical science,

Basic medical science, other

© 2024 Li Mei, Carrol Jin, Aishah Na, Jamie Marra, Simon Guan, Joanne Choi, published by Australian Society of Orthodontists Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 40 (2024): Issue 1 (January 2024)

Biomechanical aging behaviour of clear aligners

Figures & Tables

Figure 1.

Table I.

Figure 2.

Table II.

Figure 3.

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