Antimicrobial Effectiveness of Different Root Canal Irrigants on Viablility of Root Canal Flora

Introduction: Cleaning and shaping of sophisticated root canal system plays an important role in the success of endodontic treatment. In addition to root canal instrumentation, irrigation also becomes a crucial aspect in the effective disinfection of root canal system. The chemical substances like acids, chelating agents, alkaline solutions, Sodium Hypochlorite (NaOCl), oxidative agents, and normal saline are used as root canal irrigants. But each irrigant has its own limitations. With the advent of novel materials and techniques, the search for the optimal root canal irrigant still continues.

Aim: To evaluate and compare the antimicrobial effectiveness of various root canal irrigant solutions such as combination of 5.25% NaOCl and 2% Chlorhexidine gluconate, 2% Chlorhexidine gluconate, Miswak extract and normal saline for root canal irrigation.

Materials and Methods: In this prospective observational study was conducted from February 2021 to April 2021, on 10 patients with persistent endodontic infection on single rooted teeth. After obtaining access to the root canals, paper points were inserted and the soaked paper points were placed immediately in a microtube with two mL of Reduced Transport Fluid (RTF) to obtain the bacterial suspension. The sensitivity of Gram negative anerobic bacteria and E.faecalis to different irrigants was assessed with disc diffusion test and bacterial load was evaluated with Colony Forming Unit (CFU) assay. The study was analysed statistically using Kruskal-Wallis test and Dunn test (post-hoc test).

Results: The results of disk diffusion method showed that the zone of inhibition for 2% chlorhexidine gluconate was 29 mm for Gram negative anerobic bacteria and 22 mm for E.faecalis, and the zone of inhibition for Miswak extract was 8 mm for Gram negative anerobic bacteria and 10 mm for E.faecalis. Gram negative anerobic bacteria on the culture plates treated with Miswak extract had 6.41 CFU/mL, and E.faecalis had 5.21 CFU/mL. Gram negative anerobic bacteria on the culture plates treated with normal saline had a CFU/mL of 6.77, and E.faecalis had a CFU/mL of 5.77. The antibacterial activity of miswak extract was lower than that of other irrigants. The normal saline lacked any antimicrobial qualities.

Conclusion: The antibacterial effectiveness of the combination of 5.25% NaOCl and 2% Chlorhexidine gluconate was found to be higher than, 2% Chlorhexidine gluconate, Miswak extract and normal saline for root canal irrigation. A combination of 5.25% NaOCl and 2% Chlorhexidine gluconate can be used as a better choice over the other three irrigants.