Antimicrobial effectiveness of grape seed extract against Enterococcus faecalis biofilm: A Confocal Laser Scanning Microscopy analysis

Abstract This study evaluated the antimicrobial effectiveness of 6.5% Vitis vinifera grape seed extract (GSE) against Enterococcus faecalis biofilm using confocal laser scanning microscopy (CLSM). Saline solution (SS), 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) were used for comparison. Dentin discs were inoculated with E. faecalis strain establishing a 3‐week‐old biofilm. Discs ( n = 10) were exposed to 5.25% NaOCl, 2% CHX, 6.5% GSE and SS (negative control) for 10 min. Discs were stained with the fluorescent LIVE/DEAD‐BacLight™ dye and analysed using CLSM. The proportion of dead cells in biofilm was analysed using one‐way anova and Tukey tests ( P < 0.05). A higher proportion of dead cells was found in GSE group compared with CHX and SS ( P < 0.05). NaOCl group was associated with the highest proportion of dead cells ( P < 0.05). GSE presented antimicrobial activity against E. faecalis ; however, NaOCl was the most effective irrigant solution. GSE was more effective than CHX and SS.