Comparison of the use of d-enantiomeric and l-enantiomeric antimicrobial peptides incorporated in a calcium-chelating irrigant against Enterococcus faecalis root canal wall biofilms.

Abstract

OBJECTIVES:

To compare the anti-biofilm efficacy of two antimicrobial peptides (AMPs), 1018 and DJK-5, in disrupting canal wall biofilms in the isthmus, canal and dentinal tubules of single-rooted maxillary premolars.

METHODS:

Enterococcus faecalis single-species biofilms were formed in-situ in the root canal system of the premolars (n = 91). Confocal laser scanning microscopy, bacterial sampling, colony-forming unit counting, XTT assay, lactate dehydrogenase assay and phenol-sulphuric acid method were used to identify the anti-biofilm efficacy of both AMPs and their influence on bacterial metabolic activity.

RESULTS:

Both AMPs disrupted in-situ E. faecalis biofilms and altered their metabolic activity. At 20 μg/mL, the d-enantiomeric AMP DJK-5 killed 55.5 %, 57.3 % and 55.8 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, in 1 min. In contrast, the l-enantiomeric AMP 1018 only eradicated 25.6 %, 25.5 % and 27.5 % of biofilm bacteria in the isthmus, canal and dentinal tubules, respectively, within the same time. Anti-biofilm efficacy of the root canal irrigants tested were in the order: 6 % NaOCl > 20 μg/mL DJK-5 > 10 μg/mL DJK-5 > 20 μg/mL 1018 > 10 μg/mL 1018 > 0.9 % NaCl.

CONCLUSIONS:

The present results are confirmatory of previous studies, in that d-enantiomeric AMPs exhibit more potent antibacterial properties than l-enantiomeric AMPs against E. faecalis biofilms within the canal space. Nevertheless, the potency of both AMPs are concentration-dependent. Incorporation of these agents into EDTA, a non-antibacterial calcium-chelating irrigant for removal of the inorganic component of the canal space debris, does not reduce the efficacy of either AMP.

CLINICAL SIGNIFICANCE:

The present study provides the proof of concept that incorporation of an antimicrobial peptide into a calcium-chelating root canal irrigant enhances the disinfection of intratubular single-species biofilms during smear layer and smear plug removal.

• Authors: Wei-Hu Ye, Lara Yeghiasarian, Christopher W Cutler, Brian E Bergeron, Stephanie Sidow, Hockin H K Xu, Li-Na Niu, Jing-Zhi Ma, Franklin R Tay
• Journal: Journal of dentistry (J Dent) Vol. 91 Pg. 103231 (12 2019) ISSN: 1879-176X [Electronic] England
• PMID: 31712128 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Published by Elsevier Ltd.

Chemical References

• Anti-Bacterial Agents
• Peptides
• Root Canal Irrigants
• Sodium Hypochlorite
• Calcium

Topics

• Anti-Bacterial Agents (therapeutic use)
• Biofilms (drug effects)
• Calcium
• Dental Pulp Cavity (microbiology)
• Dose-Response Relationship, Drug
• Enterococcus faecalis (drug effects)
• Humans
• Peptides (therapeutic use)
• Root Canal Irrigants (therapeutic use)
• Sodium Hypochlorite