Table 4:

Antibacterial effect of essential oil obtained from seeds of Ferula assa-foetida on different bacteria based on inhibition zone diameter (mm), using the disk diffusion method

Species	Concentrations (μg/ml)*				Chlorhexidine 0.2%	P-value
	2.5	5	10	20
S. mutans	8.87±0.21	10.87±0.21	12.07±0.11	13.17±0.15	15±0.00	0.009
S. sanguis	6.94±0.11	7.93±0.30	9.90±0.2	11.94±0.20	15.53±0.57	0.009
S. sobrinus	7.93±0.15	10.16±0.15	11.03±0.2	10.06±0.11	15.07±0.12	0.013
S. salivarius	7.97±0.38	9.0±0.10	10.04±.058	12.0±0.17	15.07±0.57	0.012
L. rhamnosus	6.10±0.10	7.13±0.15	8.43±0.20	8.8±0.10	14.1±0.10	0.011

^*The inhibition zone diameters (mm) were measured triplicate to report the mean values. Chlorhexidine was the positive control in this test as the reference antimicrobial agent