Antibacterial efficacy of nisin, calcium hydroxide, and triple antibiotic paste in combination with chitosan as an intracanal medicament against Enterococcus faecalis – An in vitro study

AIMS: Evaluate and compare antibacterial efficacy of nisin, calcium hydroxide (Ca (OH)(2)), and Triple antibiotic paste (TAP) mixed with distilled water and chitosan as an intracanal medicament on Enterococcus faecalis after 1(st) and 7(th) day. SETTINGS AND DESIGN: Experimental in vitro study. MATERIALS AND METHODS: One hundred and twenty Decoronated single-rooted premolars were prepared and autoclaved. Specimens were placed in brain heart infusion (BHI) broth of a 24 h old E. faecalis (ATCC 29212) suspension. The canal was infected for 21 days, followed by grouping as-Group 1: Nisin + distilled water; Group 2: Nisin + 2% chitosan; Group 3: Ca (OH)(2) + distilled water; Group 4: Ca (OH)(2) + 2% chitosan; Group 5: TAP + distilled water; Group 6: TAP + 2% chitosan and were incubated for 1 and 7 days. Dentin scrapings from 10 specimens at each time interval were transferred into BHI broth and incubated, Serially diluted and colony-forming unit (CFU) count was assessed after 1(st) and 7(th) day. STATISTICAL ANALYSIS USED: Kruskal–Wallis test to compare mean CFUs after day 1 and day 7. Mann–Whitney post hoc Analysis to estimate significance. Wilcoxon Signed-Rank Test to compare mean CFUs between day 1 and day 7. RESULTS: After 1 day, Group 6 showed least CFUs than other groups and highest CFUs was with Group 3. There was no difference statistically when Group 5 and Group 2 were compared. After 7 days, Group 6 showed least CFUs than other groups with no significant difference between Group 1 and Group 5 as well as no significant difference between Group 2, Group 5 and Group 6. CONCLUSIONS: TAP with chitosan can be the medicament of choice for 1-day placement and was equivalent to nisin with chitosan combination after 7 days.