Characterization of Esthetic Orthodontic Wires Made from Glass-Fiber-Reinforced Thermoplastic Containing High-Strength, Small-Diameter Glass Fibers

Table 2

National Bureau of Standards (NBS) ratings.

NBS unit	Critical remarks of color differences
0.0–0.5	Trace	Extremely slight change
0.5–1.5	Slight	Slight change
1.5–3.0	Noticeable	Perceivable
3.0–6.0	Appreciable	Marked change
6.0–12.0	Much	Extremely marked change
12.0 or more	Very much	Change to other color