Effect of Disinfection Protocols on Bacterial Reduction in Mandibular Molars

Objective: This study aimed to evaluate the bacterial reduction effect of disinfection protocols used in mandibular molars infected by Enterococcus faecalis.
Methods: Eighty extracted mandibular molars were prepared and inoculated with E. faecalis for 2 months. The teeth were then divided into 2 control groups (n=4) and 4 experimental groups (n=18) according to the disin-fection protocol utilized: G1. WaveOne Gold (WOG), passive ultrasonic irrigation (PUI) and Ultracal; G2. WOG, PUI and calcium hydroxide (CH); G3. WOG, XP-Endo Finisher (XPF) and Ultracal; G4. WOG, XPF and CH. Bac-teriological samples were collected previously (S1), after preparation (S2), final agitation (S3) and intracanal dressing (S4). Microbial growth was assessed according to culture turbidity and UV spectrophotometry. Statis-tical analyses used the Friedman test for paired samples and Kruskal-Wallis test for non-paired data (p<0.05).
Results: No protocol eliminated E. faecalis effectively. The S2, S3 and S4 samples were statistically different from the S1 samples in G1, G2, G3 and G4 (p<0.05). Statistical differences were observed in bacterial reduction between G1 and G2 and G1 and G3 after the intracanal medicament (S4) (p<0.05).
Conclusion: The combination of WOG with PUI and CH disinfection protocol showed higher percentages of bacterial reduction.