Effect of Laser and Conventional Office Bleaching and Polishing on the Color Change of Stained Nanohybrid and Microhybrid Composite Resin

Table 3

Two way ANOVA test of mean color change of two composite resins after immersion in coffee solution (ΔE₁).

Source	Type III sum of squares	df	Mean square	F	Sig.
Corrected model	11.223^a	5	2.245	0.761	0.583
Intercept	1,702.706	1	1,702.706	577.144	0.000
Composite	7.813	1	7.813	2.648	0.111
Method	2.538	2	1.269	0.430	0.653
Composite method	0.871	2	0.435	0.148	0.863
Error	123.909	42	2.950
Total	1,837.839	48
Corrected total	135.132	47

^aR² = 0.083 (adjusted R² = −0.026). Interacion between composite and method and its effect on ΔE. ANOVA, analysis of variance.