Table 3.

Color differences measured in ΔE* and National Bureau of Standards units after immersion in the coffee solution

Wires	Control		1 week		2 weeks		3 weeks		4 weeks
	ΔE*	NBS units	ΔE*	NBS units	ΔE*	NBS units	ΔE*	NBS units	ΔE*	NBS units
Epoxy	0.013	0.012	0.016	0.014	0.022	0.020	0.026	0.024	0.036	0.033
Rhodium	0.018	0.016	0.024	0.022	0.030	0.028	0.036	0.033	0.039	0.036
Teflon	0.021	0.019	0.036	0.033	0.058	0.053	0.069	0.063	0.085	0.078

*P<0.05 Significant value. NBS=National Bureau of Standards