Materials and Methods: The prepared root canals of 80 teeth were contaminated with E. faecalis (n = 40) and S. epidermidis (n = 40) for 21 days to create biofilms. The samples in each group were allocated randomly into the following four subgroups (n = 10) according to the decontamination protocol: Group 1: 1% Pediocin, Group 2: 2% CHX, Group 3: Ca(OH)2, and Group 4: saline (negative control). At 5 days, the antimicrobial efficacy of the medicaments against E. faecalis and S. epidermidis was assessed by collecting dentin shavings from the canal walls created using Gates Glidden drill sizes 4 and 5, corresponding to a depth into the root canal walls of 200 μm and 400 μm, respectively. The total number of colony-forming units (CFUs) was counted. The Wilcoxon signed-rank test was used to compare the difference in CFUs between the two depths (P > 0.05).

Results: There was no bacterial growth in samples treated with pediocin, CHX, or Ca(OH)2 at either depth.