Table 3. Comparison between the studied groups regarding surface area over time.

CPC: cetylpyridinium chloride; SD: standard deviation; HSD: Tukey's honestly significant difference; P1: difference between the control and Nigella sativa groups; P2: difference between the Nigella sativa and CPC oral gel groups; P3: difference between the CPC oral gel and wheat germ oil groups; P4: difference between the control and CPC oral gel groups; P5: difference between the control and wheat germ oil groups; P6: difference between the Nigella sativa and wheat germ oil groups; F: one-way ANOVA test; ANOVA: analysis of variance; *p<0.05: statistically significant; **p≤0.001: statistically highly significant

Area	Groups				Test
	Control	Nigella sativa oil	CPC oral gel	Wheat germ oil	F	P
	Mean±SD	Mean±SD	Mean±SD	Mean±SD
Day 3	12.199±0.448	10.656±1.023	11.557±0.261	11.195±1.07	5.845	P=0.002*
HSD	P1=0.002*	P2=0.024*	P3=0.636	P4=0.39	P5=0.073	P6=0.299
Day 7	11.095±0.183	4.748±1.908	7.172±1.824	2.584±0.452	37.692	<0.001**
HSD	P1<0.001**	P2=0.005*	P3<0.001**	P4<0.001**	P5=0.011*	P6=0.013*
Day 9	9.909±0.414	1.131	2.836		187.58	0.052