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

Table 5 Correlation between color changes (ΔE) and surface roughness after one day and after 14 days in both groups

Group	After 1 day		After 14 days
Group	r	P value	r	P value
Omnichroma coffee O1	0.94	0.0001*	0.97	0.0001*
Venus Peral Coffee V1	0.95	0.0001*	0.96	0.0001*
Omnichroma distilled water O2	0.96	0.0001*	0.95	0.0001*
Venus Peral distilled water V2	0.95	0.0001*	0.97	0.0001*

ISSN: 1472-6831