[Table/Fig-6]:

Preventive effect of the tested herbal essential oils individually primed on substratum for different time periods against the in vitro formation of S. mutans biofilm.

Tested agents	Inhibitory effect against formation of S. mutans biofilm (%)± SD
	Priming time of herb on substratum (h)
	1	2	4	24
Cinnamon (bark)
MIC	67.40±5.0*	77.53±5.0*	80.50±4.0	85.42±6.0
2xMIC	73.36±6.0*	79.40±5.0*	85.48±3.0	87.01±6.0
4xMIC	80.45±2.0*,†	84.07±5.0*,†	87.63±5.0†	88.22±2.0
Sweet basil (leaf)
MIC	58.10±5.0*	64.98±4.0*	69.35±6.0	70.20±5.0
2xMIC	70.60±4.0*,†	71.44±5.0*,†	79.89±6.0†	80.09±4.0†
4xMIC	78.47±7.0*,†	78.81±5.0*,†	81.66±4.0†	86.77±3.0†
Peppermint (leaf)
MIC	55.52±7.0*	64.02±8.0*	66.55±6.0	66.60±6.0
2xMIC	66.53±8.0*,†	74.88±7.0†	77.11±4.0†	78.93±5.0†
4xMIC	73.93±5.0*,†	77.17±6.0†	82.41±2.0†	83.42±5.0†
Spearmint (leaf)
MIC	54.18±7.0*	64.72±5.0*	64.96±4.0	65.77±5.0
2xMIC	72.33±5.0*,†	74.54±6.0*,†	76.42±5.0†	77.01±5.0†
4xMIC	77.91±4.0*,†	78.21±7.0*,†	82.30±1.0†	82.75±5.0†
Black pepper (seed)
MIC	53.64±5.0*	61.78±4.0*	64.79±4.0	65.77±5.0
2xMIC	70.36±5.0*,†	71.04±3.0*,†	73.80±4.0†	78.07±3.0†
4xMIC	74.37±5.0*,†	75.51±4.0*,†	77.74±4.0†	82.74±3.0†
Sweet fennel (seed)
MIC	53.44±4.0*	60.14±6.0*	64.33±4.0	65.53±5.0
2xMIC	68.60±5.0*,†	68.90±5.0*,†	78.21±4.0†	78.81±3.0†
4xMIC	76.64±7.0*,†	78.51±5.0*,†	81.09±4.0†	84.39±3.0†
Kaffir lime (peel)
MIC	52.26±3.0*	59.64±7.0*	63.81±5.0	64.05±5.0
2xMIC	62.48±6.0*,†	68.85±5.0*,†	72.85±4.0†	76.10±3.0†
4xMIC	72.62±7.0*,†	73.47±4.0*,†	76.33±5.0†	77.98±3.0†
Kaffir lime (leaf)
MIC	52.15±4.0*	59.98±6.0*	63.81±7.0	64.72±4.0
2xMIC	62.66±6.0*,†	68.40±5.0*,†	73.31±4.0†	73.61±3.0†
4xMIC	72.42±2.0*,†	73.39±4.0*,†	77.65±4.0†	81.51±3.0†
0.25% chlorhexidine	34.42±2.0*	44.71±4.0*	52.70±2.0*	62.75±2.0

*Significantly different from the substratum primed with the agent for 24 h (p<0.05)

^†Significantly different from the substratum primed with agent at its MIC (p<0.05)