Aim: Present study was planned to assess the impact of various root canal irrigants on the adhesion of different Enterococcus faecalis (E. faecalis) strains to the dentinal surface.

Materials and methods: A total of 80 freshly extracted first and second molars were used in the present study. Preparation of dentin discs was done followed by a random division into four study groups and one control group. Four study groups included; 2.5 % sodium hypochlorite (NaOCl) , 2 % chlorhexidine (CHX), 2.5 % NaOCl + saline + 2 percent CHX and 2.5 % NaOCl + 17 % ethylene diamine tetra-acetate (EDTA) + 2.5 % NaOCl group respectively. In the control group (E), sterilized dentin discs were incubated with sterile TSB solution. Division of all the groups into two subgroups were done depending upon the type of strain of E. faecalis used. Incubation of all the specimens was done followed by assessment with XTT assay and measurement of Optical density (OD). All the results were compiled and analyzed by Statistical Package for the Social Sciences (SPSS) software.

Results: Among the groups containing gelatinase producing strains; maximum score was exhibited by 2.5 percent sodium hypochlorite solution followed by 2.5 % NaOCl + 17 % Ethylene Diamine tetra-acetate (EDTA) + 2.5 % NaOCl group (group D). On comparing the OD values among various study groups incubated with Gelatinase producing strain, significant results were obtained. Gelatinase-producing E. faecalis showed a s ignificantly h igher amount of a dherence to dentin, in comparison to the gelatinase-deficient E. faecalis strains.

Conclusion: Lesser quantity of bacteria is recovered from specimens in whom CHX was added to the irrigation protocol.

Clinical significance: Production of gelatinase by E. faecalis might lead to an increase in adhesiveness of E. faecalis to the dentin.