Eradication of Enterococcus faecalis Biofilms on Human Dentin

Abstract

Objectives: This work assesses different methods to interfere with Enterococcus faecalis biofilms formed on human dentin slabs.Methods: First, methods are presented that select for small molecule inhibitors of biofilm targets using multi-well polystyrene biofilm plates. Next, we establish methodologies to study and interfere with biofilm formation on a medically relevant model, whereby biofilms are grown on human root dentin slabs.Results: Non-conventional D-amino acid (D-Leucine) can efficiently disperse biofilms formed on dentin slabs without disturbing planktonic growth. Cation chelators interfere with biofilm formation on dentin slabs and polystyrene surfaces, and modestly impact planktonic growth. Strikingly, sodium hypochlorite, the treatment conventionally used to decontaminate infected root canal systems, was extremely toxic to planktonic bacteria, but did not eradicate biofilm cells. Instead, it induced a viable but non-culturable state in biofilm cells when grown on dentin slabs.Conclusion: Sodium hypochlorite may contribute to bacterial persistence. A combination of the methods described here can greatly contribute to the development of biofilm inhibitors and therapies to treat Enterococcus faecalis infections formed in the root canal system.

d-Amino Acids and Lactic Acid Bacteria

“…In other examples, inhibition of biofilm formation by d-amino acids has been reported in E. faecalis [30]. On the other hand, biofilm-disassembling effects by d-amino acids have been reported in B. subtilis [27], S. aureus [28], S. epidermidis [29], E. faecalis [32], and P. aeruginosa [33] ( Table 1). The types of d-amino acid disassembling biofilm formed by these bacteria are similar to that of d-amino acids with inhibitory effects on biofilm formation.…”

Disinfection of Infected Root Canals: Nanosilver Has Good Potential

“…E. faecalis also colonizes the root canal and the apex surface in the form of a biofilm . Therefore, the E. faecalis biofilm is the object that root canal disinfectant needs to remove . We next determined the antibacterial ability of nanosilver against E. faecalis biofilm.…”

Er,Cr:YSGG Laser-Activation Enhances Antimicrobial and Antibiofilm Action of Low Concentrations of Sodium Hypochlorite in Root Canals

“…Environmental conditions provided in the root canal favor polymicrobial growth. Nevertheless, Enterococcus faecalis is a frequently recovered bacterium from persistent infections [2]. E. faecalis is an aerotolerant anaerobic Gram-positive coccus, expressing several virulence factors, such as aggregation substances, enterococcal surface protein (Esp), pili (so called ebp (endocarditis and biofilm-associated pili)) and cytolysin [3].…”