Aim: To assess the effect of newly introduced delivery method of chlorohexidine versus existing forms on antibacterial properties of the material by applying on two of the most common root canal bacteria; Enterococcus faecalis and Streptococcus mutans.
Methodology: A total of ten Enterococcus fecalis and ten Streptococcus mutans strains were selectively isolated from freshly extracted human teeth on MacConckey's agar and Mitis-Salivarius agar respectively. For each bacterial strain, the antibacterial effect of three chlorohexidine formulations (foam, gel and solution) was tested via in vitro disk diffusion susceptibility assay. Zones of growth inhibition were measured and compared between the three formulations.
Results: When comparing mean ranges of zones of growth inhibition around the three formulations, it was found that the mean range was highest for chlorohexidine foam. The results were significant for both Enterococcus fecalis and Streptococcus mutans strains as suggested by the P values (0.024 & 0.0003 respectively).

Conclusion: Under the circumstances of this study, it was concluded the chlorohexidine foam had better impact on the chlorohexidine antibacterial properties.

Keywords: Chlorohexidine foam, chlorohexidine solution, chlorohexidine gel, dental canal bacteria, Streptococcus mutans, Enterococcus faecalis.