Date of Graduation


Document Type


Degree Type



School of Dentistry



Committee Chair

John G. Thomas

Committee Co-Chair

Anthony T. Borgia

Committee Member

Richard Jurevic


Introduction: The main goal of endodontics is the prevention of apical periodontitis. This condition is the result of persistent pathogenic microorganisms such as Enterococcus faecalis (E. f) and Candida albicans (C. a) remaining in the root canal systems of teeth, and the ability of those organisms to directly cause acute and chronic inflammation in the periapical tissues. The concept of the use of probiotics has not yet been evaluated in addressing endodontic disease, but probiotics have proven successful in treating periodontal disease. Taking these findings into account, this preliminary work was performed to evaluate the possible effectiveness of a probiotic cocktail in preventing the growth of two potential endodontic patogens, Enterococcus faecalis and Candida albicans..;Materials and methods: Five groups (I, II, III, IV and V) of commercial probiotics were selected and evaluated based upon numbers and concentration of organisms. Pathogenic test organisms were C. albicans (WVU Isolate Ca1028) and E. faecalis (WVU Isolate Ef01).;Phase 1 of the study was conducted by a disc diffusion assay test to evaluate zones of inhibition (ZOI) in millimeters (mm) of the selected probiotics against the E. f and C.a. Microorganisms from probiotic samples were extracted via manufacturer's recommendations and mixed by weight. Thirty (30) microliters were then placed on sterile discs. Pathogenic organisms were set to a 1 McFarland standard challenge. A five probiotic disc template on blood agar plates were inoculated with a lawn of either E. F or C. a and incubated at 37° C for 48 hours and 1 week. Two, five sterile disc templates with a lawn of either pathogenic organism were run parallel as a control.;Phase 2 was conducted by mixing 9 ml of 30% poloxamer 407 and MRS broth in a test tube with 500 ml of either E. f or C. a set at a 1 McFarland standard, together with 500ml of either Group I or Group IV probiotic mixtures, set at a 2 McFarland standard. Samples were incubated at 37°C for 48 hours, followed by serial dilutions of 10 -2, 10-4, and 10-6 for evaluation of CFU/ml counts. Controls were E. f or C. a 30% poloxamer with MRS broth and no probiotics.;Results: Phase 1: Based on a One-Way ANOVA analysis, Groups I, IV and V showed the most statistically significant results (P< 0.05) with a Mean of 7.4mm,10.05mm,11.2mm for C. a and a Mean of 6.7 mm,11.1 mm, and 12.5 mm for E. f respectively at 1 week, compared with no ZOI for the control. L. acidophilus, L. casei , L. rhamnosus and B. longum were all common strains in the probiotic cocktails selected.;Phase 2: Initial results showed a decrease to a 2 log difference and a 1 log difference for groups I and IV respectively regarding CFU/ml counts for C. a and for E. f. Probiotic Groups I and IV showed complete elimination of E. f and only probiotic colonies were present on observation.;Conclusion: Recognizing that probiotics may act differently based on their composition and concentration, this study suggests that organisms such as L. acidophillus, L. rhamnosus, L.casei and B. Longum are effective for preventing the growth of E. faecalis and C. albicans in vitro against both their planktonic and biofilm morphological stages. Further evaluations for possible use in treating endodontic infection is suggested and warranted. Additionally, Phase 2 results of the study suggest that poloxamer 407 could be utilized as an ideal probiotic delivery vehicle when mixed with appropriate probiotics and utilized as an endodontic intra-canal medicament for treating teeth that have presented with non-vital pulps.