Exploring the Potential of Nitrofurantoin for Infection Control in Regenerative Endodontics: In Vitro Study.

INTRODUCTION: This study assessed a new antimicrobial paste formulation containing nitrofurantoin for regenerative endodontics against multispecies biofilms. METHODS: Four groups of 11 single-root teeth each were tested: Negative control group (brain-heart infusion broth + micro-organisms); Hoshino 1 conventional tri-antibiotic paste group (1:1:1 ratio); Hoshino 5 group (5:5:5 ratio); Experimental group with nitrofurantoin, ciprofloxacin, and metronidazole. Minimum inhibitory concentrations of each antimicrobial were determined. A polymicrobial biofilm (Enterococcus faecalis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans) was created in root canals, and pastes were inserted for 3 minutes with lentulo. After 7 days, samples were sonicated and spectrophotometrically analyzed. Microbiological assays, plasma membrane permeabilization, confocal laser scanning microscopy, and scanning electron microscopy evaluated biofilm eradication. Statistical significance was set at P < .05. RESULTS: Spectrophotometry indicated Experimental group outperformed Hoshino 1 group and Negative control group (P < .05), with results similar to Hoshino 5 group (P > .05). Experimental group showed increased membrane damage compared to Hoshino 1 group and Hoshino 5 group. Confocal laser scanning microscopy and scanning electron microscopy revealed fewer microorganisms and no residual biofilm in Experimental group. CONCLUSIONS: Substituting minocycline with nitrofurantoin in the paste effectively reduced microorganism counts in root canals system.