A preliminary study of the antibacterial potential of cetylpyridinium chloride in root canals infected by E. faecalis

Abstract

The aim of this preliminary study was to verify the antibacterial potential of cetylpyridinium chloride (CPC) in root canals infected by Enterococcus faecalis. Forty human maxillary anterior teeth were prepared and inoculated with E. faecalis for 60 days. The teeth were randomly assigned to the following groups: 1: Root canal preparation (RCP) + 0.1% CPC with positive-pressure irrigation (PPI, Conventional, NaviTip(®)); 2: RCP + 0.2% CPC PPI; 3: RCP + 2.5% NaOCl PPI; 4: RCP + 2.5% NaOCl with negative-pressure irrigation system (NPI, EndoVac(®)); 5: Positive control; and 6: Negative control. Four teeth of each experimental group were evaluated by culture and 4 by scanning electron microscopy (SEM). In all teeth, the root canals were dried and filled with 17% EDTA (pH 7.2) for 3 min for smear layer removal. Samples from the infected root canals were collected and immersed in 7 mL of Letheen Broth (LB), followed by incubation at 37°C for 48 h. Bacterial growth was analyzed by turbidity of culture medium and then observed with a UV spectrophotometer. The irrigating solutions were further evaluated for antimicrobial effect by an agar diffusion test.The statistical data were treated by means, standard deviation, Kruskal-Wallis test and analysis of variance. Significance level was set at 5%. The results showed the presence of E. faecalis after root canal sanitization. The number of bacteria decreased after the use of CPC. In the agar diffusion test, CPC induced large microbial inhibition zones, similar to 2% chlorhexidine and large than 2.5% NaOCl. In conclusion, cetylpyridinium chloride showed antibacterial potential in endodontic infection with E. faecalis.

Effect of Passive Ultrasonic Irrigation on Enterococcus faecalis from Root Canals: An Ex Vivo Study

“…Several studies use E. faecalis to evaluate the antimicrobial effect of different medicaments, irrigants and treatment protocols (8,14,23,24). The methodology used in this study simulates the clinical infection in the RCS, using an E. faecalis 21-day incubation period, as described in previous study (21).…”

“…Immediately after irrigation, root canals in Groups PUI/NaOCl and CNI/NaOCl were filled with 1% sodium thiosulfate in order to neutralize the NaOCl (2,8). The other groups were filled with saline.…”

“…(7). Sodium hypochlorite (NaOCl) is the most widely used chemical irrigant in Endodontics, due to its antimicrobial properties (4,8,9) and its ability to dissolve organic tissues (5,10,11).…”

“…Enterococcus faecalis is the most frequently observed microorganism in persistent infections associated with endodontic failure (12), and has demonstrated the ability to invade the dentine tubules (13). Due to its great resistance, ability to organize into a biofilm and to form a monospecies infection, this microorganism has been extensively used in studies evaluating the effectiveness of irrigating solutions and intracanal medicaments (1,5,8,12,14).…”

“…Several irrigation methods have been proposed to enhance the effectiveness of NaOCl in cleaning and disinfecting the RCS and then in eliminating the microorganisms (8,15,16). Ultrasound has been used in Endodontics to complement the cleaning ability of root canal irrigants.…”