Effect of coffee on color stability and surface roughness of newly introduced single shade resin composite materials

Table 2 Mean & standard deviation of color changes (ΔE after one day and after 14)

Group	N	ΔE After 1 day		ΔE After 14 days		P value
Group	N	M	SD	M	SD	P value
Omnichroma coffee O1	15	12.46^a	1.89	16.69^a	3.52	0.002*
Venus Peral Coffee V1	15	17.09^b	5.87	26.94^b	6.21	0.0001*
Omnichroma distilled water O2	15	2.45^c	1.40	2.91^c	1.30	0.003*
Venus Peral distilled water V2	15	2.64^c	0.86	3.97^c	0.67	0.001*
P value		< 0.0001*		< 0.0001*

M Mean, SD Standard deviation, N Count
^*: Significant difference as P < 0.05
Means with the same superscript letters in the same column were insignificantly different as P > 0.05
Means with different superscript letters in the same column were significantly different as P < 0.05
^a, ^b and ^c letters describes the significance determined by Turkey's post hoc test for multiple comparisons

ISSN: 1472-6831