Evaluation of Antibacterial Efficacy of Two Commercially Available Probiotics as Intracanal Medicament against Enterococcus faecalis : An In Vitro Study.

AIM: This study was performed to evaluate the antibacterial efficacy of two commercially available probiotics (BIFILAC and VSL 3) as intracanal medicament against Enterococcus faecalis in endodontic therapy.

MATERIALS AND METHODS: Microorganisms from commercially available probiotics (BIFILAC and VSL 3) were extracted via the manufacturer's recommendations and mixed by weight. About 30 microliters were then placed on sterile discs. The pathogenic test organism was E. faecalis set to a 1 McFarland standard challenge. A two-probiotic disc template on blood agar plates was inoculated with E. faecalis and incubated at 37°C for 48 hours and 1 week respectively. Phase-1 of the study was conducted by a disc diffusion assay test to evaluate zones of inhibition (ZOI) in millimeters (mm). Phase-2 was conducted by mixing 9 mL of 30% poloxamer 407 and MRS broth in a test tube, together with the two probiotic mixtures and E. faecalis , set at a 2 McFarland standard. Serial dilutions up to 108 were done and the mixture was placed inside root canals and incubated at 37ºC for 36 hours and evaluated for colony-forming unit (CFU)/mL counts.

RESULTS: The results of phase-1 showed that probiotics Lactobacillus rhamnosus and Bifidobacterium species are effective in fighting against E. faecalis with the acceptable zone of inhibition. The results of phase-2 showed that both the probiotics are effective against E. faecalis with a reduction in the number of CFU after probiotic usage.

CONCLUSION: Commercially available probiotics can be used effectively as an intracanal medicament to fight against E. faecalis , Poloxamer 407 is a promising vehicle for delivering probiotics inside the root canal system. Further in vitro and in vivo studies are needed to determine the full potential of "Bacteriotherapy" with an application of probiotics.

CLINICAL SIGNIFICANCE: If probiotics are proved to be an effective intracanal medicament against E.faecalis they can be used as an alternative to calcium hydroxide as intracanal medicament with no side effects to the host.