. 2019 Feb 26;11(1):16–22. doi: 10.4047/jap.2019.11.1.16

Table 4. Changes of color coordinates and t-test results of materials between before and after glazing of each thickness.

Thickness (mm)	Color coordinate	EM		ZP		P value
Thickness (mm)	Color coordinate	Mean	SD	Mean	SD	P value
0.6	∆L^*	−2.28	1.55	−0.92	1.15	.044^*
	∆a^*	−0.35	0.14	−0.25	0.24	.262
	∆b^*	0.36	0.93	0.23	1.88	.847
	∆E^*	2.61	1.35	2.09	1.15	.367
1.0	∆L^*	−1.16	0.79	−1.33	1.02	.675
	∆a^*	−0.01	0.12	−0.34	0.17	.000^*
	∆b^*	1.24	3.29	0.10	0.79	.301
	∆E^*	3.17	1.88	1.65	0.87	.033^*

EM: IPS e.max Press, ZP: IPS e.max ZirPress.

^*Significantly different compared to test groups (P < .05)