Table 1.

Absorbance values of the three aligners before and after in vitro aging

Aligner	Absorbance at 400 nm (±SD)			Absorbance at 700 nm (±SD)
	As received	After aging	Significance	As received	After aging	Significance
All-In	0.265 ± 0.036	0.278 ± 0.011	N.S.	0.209 ± 0.030	0.215 ± 0.008	N.S.
Invisalign	0.172 ± 0.004	0.190 ± 0.03	N.S.	0.143 ± 0.004	0.155 ± 0.023	N.S.
F22	0.107 ± 0.023	0.104 ± 0.003	N.S.	0.090 ± 0.024	0.081 ± 0.004	N.S.

N.S. not significant variation