Table 1.

List of relevant information for all retainers investigated: manufacturer, product name, material composition, and manufacturing process. CAD/CAM computer-aided design/computer-aided manufacturing

	Manufacturer	Product name	Material composition of retainer alloy (%)	Manufacturing process
1	Ormco (Orange, CA, USA)	“Respond” archwire	Stainless-steel alloy 304 (carbon: 0.08; chromium: 10.8/20.0; nickel: 8/10.5; magnesium: 2.0; silicon: 1.00; rest: iron)	Bending
2	Ortholize (Nienhagen, Germany)	No specific product name	Cobalt-chromium alloy (cobalt: 60; chromium: 28; wolfram: 9; silicon 1.5; magnesium, nitrogen, niobium, iron: all < 1)	CAD/CAM (laser melting)
3	Fachlabor Klee (Frankfurt, Germany)	“3D Swiss Retainer”	Grade-5 titanium (aluminum: 5.5; vanadium: 3.5; iron, oxygen, nitrogen, carbon, hydrogen: all < 1; rest: titanium)	CAD/CAM (milling)
4	CA Digital (Hilden, Germany)	“Memotain”	Nitinol (nickel: 55; titanium: 45; oxygen, nitrogen, carbon: all < 1)	CAD/CAM (laser cutting)