Assessment of antimicrobial activity of sodium hypochlorite, calcium hypochlorite and grape seed extract against Enterococcus faecalis

Abstract

OBJECTIVE: This study aimed to assess the antimicrobial action of calcium hypochlorite [Ca(OCl) 2 ] at concentrations of 2.5% and 6%, and of grape seed extract (GSE) at concentrations of 10%, 30%, and 50%, against Enterococcus faecalis, comparing it to the action of 6% sodium hypochlorite (NaOCl). METHODS: Saline solution was used as negative control. The inhibition halos of microbial growth were verified by the agar disk diffusion method. Twelve Petri plates were used for seeding with culture medium of approximately 5 mm in thickness. In each plate, 5 disks of pure and sterile antibiogram, soaked in the substances to be tested, were used and taken to the plate containing the seeded bacterial strain. The plates remained in aerobic bacteriological incubator for 24 h at 37°C temperature. After 24 h, the inhibition halos were measured with a digital caliper. Analysis of Variance (ANOVA) was used for statistical analysis followed by Tukey's complementary test, at 5% significance. RESULTS: The 6% Ca(ClO) 2 presented inhibition halo statistically higher than the other solutions (p<0.05), followed by 2.5% Ca(ClO) 2 , which was statistically similar to 6% NaOCl (p>0.05). The GSE concentrations resulted in lower inhibition halos of active substances and the different concentrations were similar to each other. Lastly, saline solution presented the same inhibition halos in all groups (p<0.05). CONCLUSION: It may be concluded that 6% Ca(OCl) 2 presented higher antimicrobial activity than 6% NaOCl. On the other hand, all GSE concentrations were lower than NaOCl and Ca(OCl) 2 .