Antimicrobial Efficacy of Chlorhexidine and Two Calcium Hydroxide Formulations Against Enterococcus faecalis

Abstract

The purpose of this study was to investigate the efficacy of chlorhexidine (CHX) and calcium hydroxide (Ca(OH2) against Enterococcus faecalis in vitro. Extracted single-rooted human teeth were instrumented up to size 40. After removal of the smear layer, an inoculum of E. faecalis was inserted into the root canals. After incubation, the inoculum was removed and the root canals were filled with one of three different disinfectants: Ca(OH2 paste, CHX 2%, and a mixture of CHX and Ca(OH2 paste (n = 10 in each group). Control teeth were filled with water of standardized hardness (n = 10). The teeth were then incubated for 3 days. After incubation, each root canal was instrumented, and the removed dentin was examined microbiologically. CHX was significantly more effective against E. faecalis than was Ca(OH2 paste or a mixture of CHX with Ca(OH2 paste (p < 0.05). There was no increase in the efficiency of Ca(OH2 paste when CHX was added (p > 0.05). The results suggest that CHX is effective in the elimination of E. faecalis from dentinal tubules under the conditions of this study.

Antibacterial effect of triantibiotic mixture versus calcium hydroxide in combination with active agents against Enterococcus faecalis biofilm

“…This is in accordance with the findings of other reports 29,30,[35][36][37] . These results can be due to the similar pH values of CH solutions when combined with other irrigants or medications (Table 2).…”

“…CH is widely used as intracanal medication due to its organic tissue dissolution potential 26) , antibacterial activity 27) , and antiinflammatory capacity 28) . Since CH is ineffective in elimination of some microorganisms such as E. faecalis, to improve its antibacterial activity, it has been combined with other materials [29][30][31][32][33][34][35][36][37][38] . In the present study, to evaluate the combination potential of CH, it was combined with two established endodontic irrigants (CHX, NaOCl) and COL a medication with possible antibacterial potentials.…”

“…This model provides reconstruction of the microanatomy of dentin, simulates the chemical environment of the root canal system, and allows biofilm development 40) . Numerous studies have evaluated the antibacterial effect of CH alone or in combination with different materials using the dentin block model [30][31][32][33][34][35][36][37][38] . However, there is still controversy on whether combination of CH with other active agents enhances its antibacterial potential.…”

“…This strain easily penetrates into dentinal tubules 41) . Since this bacterium is highly resistant against different antibacterial agents, it has been used to evaluate the antibacterial effectiveness of different intracanal medications in various studies 20,[30][31][32][34][35][36][37]43) . Accordingly, this strain was selected as a measure for antibacterial property of selected medications in the present investigation.…”

Penetration Depth of Sodium Hypochlorite in Dentinal Tubules after Conventional Irrigation, Passive Ultrasonic Agitation and Nd:YAG Laser Activated Irrigation

“…35 Further studies, reported the maximum penetration depth of bacteria in the pulpal dentin wall to be up to 0.25 mm. 36 On the other hand, Siqueira et al observed bacterial cells up to an approximate depth of 300 microns and believed that low penetration depth was more conventional. 13 Also, resistant infections resulting from reproduction of the remaining bacteria inside dentinal tubules are one of the probable reasons for treatment failure.…”