Influence of Endodontic Procedure on the Adherence of Enterococcus faecalis.

The purpose of this study was to investigate the effects of instrumentation and irrigation on the initial adherence of Enterococcus faecalis to root canal dentin and to explore initial microbial adhesion to root filling materials. The following specimens were prepared: instrumented and uninstrumented dentin, dentin treated with different irrigation protocols, and root filling materials. The number of E. faecalis cells adhered on dentin was measured. The adhesion force of E. faecalis cells on different materials and the roughness of different surfaces were measured. The contact angle of the surfaces was recorded. The results were analyzed using the t test. Instrumented dentin specimens had a significantly higher amount of E. faecalis adherence than uninstrumented dentin. There were higher numbers of adhering bacteria on the dentin when EDTA was used alone (P <.05) compared with other irrigants alone. The use of chlorhexidine (CHX) as the last irrigant for a certain time resulted in a reduced number of adhering bacteria when the specimens were first exposed to sodium hypochlorite (NaOCl) followed by EDTA. EDTA used alone had the highest adhesion force followed by NaOCl alone and CHX alone (P <.05). Dentin treated with EDTA alone had the highest roughness and contact angle followed by NaOCl alone and CHX alone (P <.05). CHX added as the final irrigant after NaOCl with EDTA irrigation reduced the contact angle (P <.05). Larger amounts of adhering bacteria and higher adhesion force were detected on the surface of gutta-percha and sealer than on the dentin surface (P <.05). Instrumentation and irrigation alter the initial adherence of E. faecalis to root canal dentin and the surface properties of the dentin as well. • Instrumented dentin had more E. faecalis adherence than uninstrumented dentin. • The longer irrigation time resulted in less adhering bacteria on the dentin. • Root filling material had higher adhesion activity compared with dentin. [ABSTRACT FROM AUTHOR]