Effectiveness of final decontamination protocols against Enterococcus faecalis and its influence on bond strength of filling material to root canal dentin

Abstract

AimThe aim of this study was to evaluate the effectiveness of final decontamination protocols against Enterococcus faecalis and their influence on bond strength of filling material to root canal dentin. Material and methodsNinety root canals were enlarged with ProTaper system and inoculated with E. faecalis for 15days. Sixty samples were randomly divided into six groups (n=10) and subjected to following protocols: G1-distilled water(control), G2-2% chlorhexidine, G3-QMix, G4-6.5% grape seed extract, G5-photodynamic therapy with optical fiber and G6-photodynamic therapy without optical fiber. The percentage of bacterial reduction was checked by counting of CFUs. The remaining 30 samples were subjected to the same decontamination protocols (n=5) and filled with gutta-percha and AH Plus sealer in order to perform the push-out test. Data from both tests were subjected to one-way ANOVA followed by Tukey’s post hoc procedure (α=0.05). ResultsThe greatest bacterial reduction was observed for 2% chlorhexidine, QMix and 6.5% grape seed extract, with no statistically significant difference between them. Photodynamic therapy, with and without optical fiber, demonstrated a significantly higher reduction than distilled water, with no statistically significant difference between them (p<0.05). For the push-out test, final decontamination protocols showed similar bond strength values (p<0.05), with the highest incidence of cohesive failure in all groups. ConclusionsThe tested final decontamination protocols showed effectiveness against E. faecalis and did not interfere with the bond strength of filling material to root canal dentin.