Clinical Evaluation of Etched Enamel Discoloration following Immediate and Delayed Exposure to Colored Agents

Table 2

The results of the Sign test for Comparison of Δ𝐸 of etched and unetched enamel in the four groups.

	Group
	Group I	Group II	Group III	Group IV
Exact significant (2-tailed)	0.804	0.210	0.077*	0.077*
Exact significant (1-tailed)	0.402	0.105	0.038*	0.038*

∗Statistical significant.