Residual activity of cetrimide and chlorhexidine on Enterococcus faecalis-infected root canals

Abstract

Effective final irrigation regimen is an important step in order to achieve better disinfection and ensure residual antimicrobial effects after root canal preparation. The aim of this study was to compare the residual antimicrobial activity of 0.2% cetrimide, and 0.2% and 2% chlorhexidine in root canals infected with Enterococcus faecalis. Biofilms of E. faecalis were grown on uniradicular roots for 4 weeks. After root canal preparation, root canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA) to remove the smear layer. The roots were randomly divided into three experimental groups (n=26) according to the final irrigating solution: Group I, 5 mL 0.2% cetrimide; Group II, 5 mL 0.2% chlorhexidine; and Group III, 5 mL 2% chlorhexidine. Samples were collected for 50 days to denote the presence of bacterial growth. The proportion of ungrown specimens over 50 days was evaluated using the nonparametric Kaplan–Meier survival analysis. Differences among groups were tested using the log-rank test and the level of statistical significance was set at P<0.05. The highest survival value was found with 2% chlorhexidine, showing statistically significant differences from the other two groups. At 50 days, E. faecalis growth was detected in 69.23% specimens in Groups I and II, and in 34.61% specimens of Group III. There were no significant differences between 0.2% cetrimide and 0.2% chlorhexidine. Final irrigation with 2% chlorhexidine showed greater residual activity than 0.2% chlorhexidine and 0.2% cetrimide in root canals infected with E. faecalis.

Evaluation of the Effect of Enterococcus faecalis Biofilm on the 2% Chlorhexidine Substantivity: An In Vitro Study

“…Previous studies (17,20) have reported periods of substantivity that are longer than those observed in the present study (up to 90 days). However, they did not associate the amount of CHX present in the final evaluation period to the efficient microbial control.…”

“…Therefore, a 5-minute application can be clinically accepted as a final flushing. Ferrer-Luque et al (20) showed that 2% CHX solution possesses an antimicrobial residual effect during a 50-day period after 1 minute of contact. With a longer contact time (such as during root canal preparation), Souza et al (17) observed the presence of CHX solution after 90 days.…”

“…Several methodologies (12,(16)(17)(18)20) were implemented to assess the maintenance of residual antimicrobial effect although there are few studies showing that CHX would maintain this residual effect on infected human dentin for periods longer than 72 hours. Furthermore, there are no previous studies that correlate the CHX retained in dentin and the bacterial cell viability for a 30-day period.…”

“…Studies have shown that chlorhexidine (CHX) is able to adsorb onto the dentin walls (substantivity), providing long-lasting antimicrobial effects (12)(13)(14)(15)(16)(17)(18)(19)(20). In this regard, different evaluation periods are considered.…”

Effectiveness of 2% Chlorhexidine on Removal of E.FAECALIS Biofilm in Root Canal: A Systematic Review.

“…Flow cytometry shows that ozone and chlorhexidine act differently, which could explain its synergic activity. This new disinfection protocol, combining irrigation with chlorhexidine at 2% and ozone gas for 24 seconds, may be advantageous when treating infected root canals [21] .…”