The antimicrobial effect of different ozone protocols applied in severe curved canals contaminated with Enterococcus faecalis: ex vivo study

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals

“…Several microorganisms and their byproducts are involved in the etiology of endodontic infections, including E. faecalis, which can invade dentinal tubules, shows strong adhesion to collagen, and is resistant to irrigating solutions commonly used during root canal instrumentation 15 . Given the great ability of this microorganism to survive root canal disinfection, biofilms of E. faecalis have been widely used in research settings 6 , 12 , 14 , 16 , 17 . However, because more than 150 species can colonize the root canal system 2 , the present study used mature multispecies biofilms containing E. faecalis , C. albicans , and S. aureus, microorganisms that are equally resistant and contribute to persistent intracanal infection, as done in previous studies using multispecies biofilms 15 , 18 .…”

“…In addition, it is important to highlight the biofilm formation time of 21 days, as used in previous studies 12 , 15 , 17 , 18 . In contrast, there are studies with younger biofilms, such as the one conducted by Hubbezoglu et al 6 , who waited 24 hours for biofilm formation.…”

“…Agitation potentiates the effects of the irrigant, which can be agitated by PUI 3 , 16 , 21 , 22 , continuous ultrasonic irrigation 12 , sonic agitation using the EA system 17 , 21 , and manual dynamic activation 21 . In the current study, the irrigants were agitated by PUI, a technique with some limitations such as the Irrisonic tip working until 2 mm short of the working length.…”

“…Another sampling method involves stroking the canal walls with a Hedstroem file in order to collect bacteria from deep in the biofilm, as performed by Case et al. 3 and by Moraes et al 12 . However, according to Siqueira and Rôças 23 , although files can obtain more visible material, this sampling method makes it difficult to control contamination, especially when the file is severed after sample collection, files cannot sample much deeper than paper points, and there are no studies demonstrating that one method is superior to the other.…”

“…The local research ethics committee (protocol number 5.129.512) approved this study. The sample size of 15 specimens per group was based on the results of a pilot test and the study by Moraes et al 12 . The sample size was calculated by analysis of variance (ANOVA) for a minimum difference between the treatment means of 0.12, an error deviation of 0.085, number of treatments of 7, power of 0.80, and alpha of 0.05.…”