Table 3.

Optical density in crystal violet assay of Streptococcus mutans and Candida albicans mixed biofilm according to the treatment

Treatment	Optical density (at 570 nm)
	C1		C2		Negative control
	Mean	SD	Mean	SD	Mean	SD
Chlorhexidine	0.180ABC	0.036	0.181AB	0.050	0.416	0.074
Nystatin	0.218AC	0.044	0.228AB	0.068	0.416	0.074
Chlorhexidine/30 min/nystatin	0.210A	0.031	0.240AB	0.089	0.373	0.167
Nystatin/30 min/chlorhexidine	0.199AC	0.030	0.241A	0.052	0.373	0.167
Chlorhexidine/1 min/nystatin	0.161BC	0.013	0.153B	0.021	0.352	0.173
Nystatin/2 min/chlorhexidine	0.143B	0.014	0.144B	0.014	0.352	0.173
Chlorhexidine/10 min/nystatin	0.191AC	0.027	0.192AB	0.053	0.442	0.189
Nystatin/10 min/chlorhexidine	0.191AC	0.027	0.192AB	0.053	0.442	0.189
Chlorhexidine/nystatin single	0.168ABC	0.021	0.172AB	0.020	0.474	0.180
P*	0.000		0.000

C1 2 μg/mL chlorhexidine and 1 μg/mL nystatin, C2 1 μg/mL chlorhexidine and 0.5 μg/mL nystatin. SD standard deviation

^*P value for ANOVA comparing the treatments within each concentration; means followed by different letters in the same column differ significantly (α = 0.05) by Dunnett’s T3 multiple comparisons test

Negative control mixed biofilm without drugs; not included in the statistical analysis