Impact of Different Irrigant Agitation Methods on Bacterial Elimination from Infected Root Canals

Abstract

Activation techniques are essential for root canal disinfection but may result in incomplete removal of bacteria. The aim of our study was to assess the antibacterial action of sonically, ultrasonically and laser-activated irrigation and 5.25% sodium hypochlorite (NaOCl) on Enterococcus faecalis in an infected tooth. Forty-four extracted mandibular premolars were mechanically prepared, sterilized, and inoculated with E. faecalis for 1 week. Bacterial counts after inoculation were evaluated in 4 randomly chosen teeth, remaining root canals were divided into 4 groups. Group A: laser-activated irrigation by photon-induced photoacoustic streaming, Group B: the sonic irrigation by EDDY, Group C: ultrasonic irrigation by EndoUltra, and Group D: 5.25% NaOCl. Colony forming unit (CFU) counts were measured and Kolmogorov–Smirnov, Wilcoxon, Kruskal–Wallis and Mann–Whitney tests were used to determine differences. The mean of CFU was found to significantly decrease in group D, 2110 ± 1015.93 (p < 0.001). Changes in measurement levels followed the same trend over time in groups A 27.40 ± 30.15, B 81.3 ± 85.68 and C 44.40 ± 67.12 (p = 0.141). The average CFU after irrigation in all groups was significantly greater than 0. Within the limitations of this study, all activation techniques were superior to NaOCl 5.25% in reducing E. faecalis from the infected tooth model.

Sonic irrigant activation for root canal disinfection: power modes matter!

“…Considering the limited reach of sonically activated irrigants in dentinal tubules, it has been argued that the concentration of NaOCl is more important than sonic irrigant activation to eliminate bacteria residing in dentinal tubules [22]. The present investigation confirms that sonic irrigant activation with EDDY, employed at the highest power setting, outperforms the antimicrobial effect of manual syringe irrigation but, in contrast to the studies of Hage et al [23] and Zeng et al [22], no viable microorganism were found even after an extended re-incubation period of seven days. In addition to different microbiological assays and variations in the irrigation protocols, the different makeup of tooth samples may account, at least to some degree, for these conflicting microbiological results.…”

“…In addition to different microbiological assays and variations in the irrigation protocols, the different makeup of tooth samples may account, at least to some degree, for these conflicting microbiological results. In the studies of Hage et al [23] and Zeng et al [22] exclusively single-rooted premolars were used whereas the sample of the present study included anterior teeth, premolars and palatal roots of maxillary molars. Premolars are frequently extracted in adolescence and early adulthood for orthodontic reasons.…”

“…This may influence the antimicrobial effect of irrigation protocols [17,24]. A tentative conclusion that can be drawn based on the results of the studies which assessed the antibacterial efficacy of the EDDY device is that sonic irrigant activation is advantageous compared with manual syringe irrigation but cases with severe intratubular infection may still require adjunct measures such as the use of higher NaOCl concentrations and prolonged exposure times [22,23,25].…”

Effect of Needle Size and Volumetric Flow Rate on Root Canal Irrigation: A Numerical Investigation

“…In root canal therapy it is crucial to decrease bacterial population which colonize the root canal as much as possible [1]. The most conventional approach used for disinfecting the root canal is employing antimicrobial agents for irrigating.…”

“…The most conventional approach used for disinfecting the root canal is employing antimicrobial agents for irrigating. The irrigation performance can be improved by some methods such as sonically or ultrasonically activations [1]. Several agents are applicable as irrigant in root canal disinfection such as silver Nano fluid, sodium hypochlorite and chlorhexidine digluconate (CHX) [2,3].…”