## 4 Discussion  
Using the same methods of determination, UV field photo spectrometry, [PERSON] et al. (2012) analyzed the content of polyphenols and flavonoids of an aqueous extract of concentration 110 mg/mL of _Epilobium parviform_ Schreb. with a total content of 10.45 Eq. chlorogenic acid/g vegetable powder polyphenols and 31.9 mg EqPir/g vegetable powder flavonoids. Although difficult to compare in terms of the amount of polyphenols, because different controls were used for calibration, the data in our study show the presence of polyphenols in a higher amount in hydroalcoholic extracts than in aqueous ones because the alcohol mixed with water acquires a power of higher dissolution and ensures a better yield. Regarding the amount of flavonoids, this is higher in the study carried out by [PERSON] compared to the level determined in the present study from the two extracts,  
Figure 12: _Escherichia coli._ (**d**) hydroalcoholic vegetable extract; (**e**) ultrasonicated hydroalcoholic vegetable extract; (**f**) aqueous vegetable extract. Figure 13: _Enterococcus faecalis._ (**a**) NaOC1 5.25%; (**b**) CHX 2%; (**c**) NaOC1 2%; (**d**) hydroalcoholic vegetable extract; (**e**) ultrasonicated hydroalcoholic vegetable extract; (**f**) aqueous vegetable extract. both aqueous (0.86 EqQr/g vegetable powder) and hydroalcoholic (2.87 EqQr/g vegetable powder); one of the possible reasons why it is found in larger quantities would be the temperature at which the extraction was carried out (40 \({}^{\circ}\)C) and the crushing of the plant to the powder stage, thus increasing the contact surface between the plant and the solvent [33]. A very recent study ([PERSON] et al., 2021) used UV field photo spectrometry to analyze the content of polyphenols and flavonoids of a 40% ethanolic extract of _Epilobium parviform_ Schreb. Although difficult to compare in terms of the amount of polyphenols and flavonoids, because different controls were used for calibration, the data in our study show the presence of polyphenols (16.79 \(\upmu\)g/\(\upmu\)L Gallic Acid equivalent) and flavonoids (2.87 \(\upmu\)g/\(\upmu\)L Catechin equivalent) above the one founded by [PERSON] et al. [34]. The constituent compounds of a plant extract obtained from _Epilobium parviform_ Schreb. by the method of hydrodistillation was determined in a study by [PERSON] et al. (2017), among which were 40% alcohols and 13.8% polyphenols, with the remaining percentages being occupied by esters, aldehydes, ketones, aromatic hydrocarbons. Although the method for determining the biologically active compounds is completely different from that of the present study, the results obtained compete with those found by [PERSON] who demonstrated the existence of polyphenols in the extract of _Epilobium parviform_ Schreb. The results of the present study show that extracts obtained from _Epilobium parviform_ [PERSON] are effective on strains isolated from pathological products taken from patients with endodontic pathology, being in competition with those obtained by [PERSON], although both antibacterial activity and the type of bacterial strains were achieved by different methods in the two studies [35]. The evaluation of the level of efficacy shows that there are differences between Gram-positive and Gram-negative bacteria, so the strains of White _Staphylococcus_, _Streptococcus mitis_ and _Streptococcus sanguis_ proved to be the most sensitive to these extracts, maintaining that the hydroalcoholic ones were the most effective. Of all the strains tested, the hydroalcoholic extracts were the most effective, compared to the aqueous plant extracts. The lowest level of sensitivity to the tested solutions had the bacteria from the group of Gram-positive shells, specifically _Enterococcus faecalis_, a bacterial species with established resistance to antibiotics. There were no significant differences in antibacterial action between the hydroalcoholic and ultrasonicated extracts.