The Antibacterial Effect of QMix, a Novel Root Canal Irrigant (Ex vivo Study)

Aims: To evaluate the antibacterial effect of a novel root canal irrigant, QMix, by evaluating its effect against E. faecalis and comparing it to 17% EDTA and 2% Chlorhexidine digluconate. Materials and Methods: Minimum Inhibitory Concentration (MIC), Minimum bactericidal concentration (MBC) and direct exposure test were the techniques used. In the MIC and MBC technique, the irrigants (QMix, 17% EDTA, 2% CHX) were serially diluted in BHI broth and 0.2 mL of the tested bacterial suspensions was added. Results were obtained on the basis of turbidity and growth on agar plates. In the direct exposure test, Enterococcus faecalis were exposed to QMix, 2% Chlorhexidinedigluconate and 17% EDTA for 5 seconds, 30 seconds and 3 minutes. Following exposure, samples were taken and serially diluted and incubated anaerobically on E. faecalis selective media for 24 hours to count the resistance of the bacteria. Results: In the MIC and MBC technique, CHX showed to be more effective against E. faecalis than both QMix and EDTA, as lower dilutions were required to inhibit growth of both bacteria. Ethylene diamine tetra acid (EDTA) was the least effective. In the direct exposure test, QMix was more effective than CHX and EDTA as it was the only solution to be able to kill all bacteria. Few E. faecalis cells remained even after exposure of bacteria to 3 minutes of EDTA and CHX. There was significant difference between QMix and both EDTA and CHX in killing of E. feacalis at 5 seconds exposure (p<0.05). QMix killed more than 95% of bacteria, whereas CHX and EDTA killed fewer than 20% (p<0.05). There was no statistical significance between the irrigant solutions at 3 minutes of exposure. Conclusions: In the MIC The Antibacterial Effect of QMix, a Novel Root Canal Irrigant (Ex vivo Study) ISSN: 1812–1217 Al – Rafidain Dent J Vol. 13, No3, 2013 www.rafidaindentj.net 538 and MBC techniques, Chlorhexidinedigluconate was found superior to both QMix and EDTA. In the Direct Exposure Test, QMix showed the best performance as it was the only irrigant solution to kill all E. faecalis cells, as well as killing more than 95% of all bacteria at 5 seconds exposure.