Chitosan nanoparticles enhance the antibacterial activity of chlorhexidine in collagen membranes used for periapical guided tissue regeneration.

Endodontic failure is mainly associated with the persistence of microbial infection in the root canal system and/or the periradicular area. Microorganisms and their toxins located in the root canal system may trigger apical periodontitis and tissue destruction. Tissue regeneration in periapical surgery by using membrane barriers has shown an improved healing and bone closure. However, bacterial membrane contamination is a main reason of failure. In this in vitro study, different brands of chlorhexidine, a combination of chitosan nanoparticles containing chlorhexidine were tested against Enterococcus faecalis on agar plate's cultures and infected collagen membranes. Our results indicated that chitosan nanoparticles acted synergistically with chlorhexidine, inhibiting and eliminating significantly a greater amount of colony former units in both BHI-agar cultures and infected collagen membranes. These results suggested that chitosan nanoparticles could be used to improve regenerative procedures in periapical surgery.