## 3 Results and Discussion
### Inhibition of Nanoparticles of Garlic Extract on the Different Bacteria
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Garlic Extract (mg/mL)**} & \multicolumn{4}{c}{**Inhibition Zone (mm)**} \\ \cline{2-5}  & _S. mutans_ & _S. aureus sub. aureus_ & _E. coli_ & _P. gingivalis_ \\ \hline
5 & 0.0 \(\pm\) 0.0 g & 0.0 \(\pm\) 0.0 e & 0.0 \(\pm\) 0.0 e & 0.0 \(\pm\) 0.0 g \\ \hline
10 & 0.0 \(\pm\) 0.0 g & 0.0 \(\pm\) 0.0 e & 0.0 \(\pm\) 0.0 e & 0.0 \(\pm\) 0.0 g \\ \hline
20 & 15.6 \(\pm\) 0.6 f & 0.0 \(\pm\) 0.0 e & 0.0 \(\pm\) 0.0 e & 14.6 \(\pm\) 0.7 f \\ \hline
40 & 22.2 \(\pm\) 0.4 e & 17.3 \(\pm\) 0.8 d & 16.2 \(\pm\) 0.7 d & 21.1 \(\pm\) 0.4 e \\ \hline
60 & 24.5 \(\pm\) 0.9 d & 18.9 \(\pm\) 1.5 c & 17.4 \(\pm\) 0.4 c & 23.6 \(\pm\) 0.5 d \\ \hline
80 & 26.8 \(\pm\) 0.6 c & 20.0 \(\pm\) 1.1 c & 18.1 \(\pm\) 0.4 c & 25.2 \(\pm\) 0.9 c \\ \hline
100 & 28.7 \(\pm\) 0.9 b & 21.4 \(\pm\) 0.5 b & 19.3 \(\pm\) 0.6 b & 27.1 \(\pm\) 0.7 b \\ \hline Standard & 34.1 \(\pm\) 0.0 a & 27.2 \(\pm\) 0.0 a & 25.5 \(\pm\) 0.0 a & 35.4 \(\pm\) 0.0 a \\ \hline R-Square & 0.9985 & 0.9967 & 0.9990 & 0.9987 \\ \hline Coeff Var & 2.94 & 5.60 & 3.05 & 2.82 \\ \hline Root MSE & 0.56 & 0.73 & 0.37 & 0.52 \\ \hline \hline \end{tabular} Values are the mean \(\pm\) standard deviation (S.D.) of three replicates. According to [PERSON]’s multiple range test, S.D. within a column followed by different letters are significantly different at \(p\leq\) 0.05 level. Coeff Var: coefficient of variation; Root MSE: Root-mean-square deviation.  
\end{table} 
Table 2: Antibacterial activity of nanoparticles (supernatant) of garlic extract against _S. mutans_, _S. aureus_, _E. coli_, and _P. gingivalis_ by agar well diffusion method. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Garlic Extract (40 mg/mL)**} & \multicolumn{4}{c}{**Inhibition Zone (mm)**} \\ \cline{2-5}  & _S. mutans_ & _S. aureus sub. aureus_ & _E. coli_ & _P. gingivalis_ \\ \hline Extract without sonication & 16.4 \(\pm\) 0.5 d & 12.7 \(\pm\) 0.3 d & 11.7 \(\pm\) 0.4 d & 15.1 \(\pm\) 0.3 d \\ \hline Sonicated without centrifugation & 18.6 \(\pm\) 0.5 c & 14.7 \(\pm\) 0.4 c & 13.5 \(\pm\) 0.3 c & 17.5 \(\pm\) 0.6 c \\ \hline Sonicated supernatant & 19.5 \(\pm\) 0.5 b & 15.5 \(\pm\) 0.4 b & 14.5 \(\pm\) 0.5 b & 18.7 \(\pm\) 0.9 b \\ \hline Standard & 33.0 \(\pm\) 0.0 a & 26.3 \(\pm\) 0.0 a & 24.1 \(\pm\) 0.0 a & 34.2 \(\pm\) 0.0 a \\ \hline R-Square & 0.9973 & 0.9976 & 0.9967 & 0.9960 \\ \hline Coeff Var & 1.88 & 1.84 & 2.12 & 2.73 \\ \hline Root MSE & 0.41 & 0.32 & 0.34 & 0.59 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Antibacterial activity of 40 mg/mL garlic extracts treated in different conditions by agar disk diffusion method. against _S. mutans_[35]. The antibacterial activity of garlic is due to its phytochemicals such as allicin, flavonoids, polyphenols, and sulfur compounds [23; 24; 25; 26; 27]. _Escherichia coli_ was the least susceptible and showed the minimum sensibility when tested against 40 mg/mL with a corresponding inhibition zone of 14.2 \(\pm\) 0.8 mm and 16.3 \(\pm\) 0.7 mm using the agar disk diffusion and agar well diffusion methods, respectively. The positive control result (streptomycin) confirmed that the bacteria were susceptible to streptomycin, the bacteria had various diameters of inhibition zones of 33.0, 31.9, 26.3, and 24.1 mm around the disk for _S. mutans_, _P. gingivalis_, _S. aureus_ sub. _Aureus_, and _E. coli_, respectively, when tested by using agar disk diffusion (Table 1). Similarly, the antibacterial activity of garlic extracts was also found to be less effective against _E. coli_ and _S. aureus_[36; 37; 38]. On the other hand, the present study proved that all tested bacteria were resistant to 5 mg/mL and 10 mg/mL. Moreover, both _E. coli and S. aureus_ sub. _aureus_ were resistant specifically to 20 mg/mL. These results are in agreement with [PERSON] [32], who assessed the antibacterial activity of garlic extract against _S. aureus_ and found that concentrations of garlic extract ranging from 10 to 20 mg/mL were unable to inhibit the growth of _S. aureus_.