The inhibitory effect of quaternary ammonium salt on bacteria in root canal

Sanjay Kumar Tiwari,Xuedong Zhou,Lei Cheng,Hockin H K Xu,Xiao Guo,Xian Peng,Biao Ren,Yannan Huang,Michael D Weir,Mingyun Li

doi:10.1038/s41598-019-48666-4

Sanjay Kumar Tiwari, Xuedong Zhou + Show 8 more

Open Access

https://doi.org/10.1038/s41598-019-48666-4

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Abstract

Persisting apical periodontitis is a primary reason for multiple intervention in root canal. Persisting bacteria in root canal is related with the persisting infection. Despite the advancement in treatment strategies the persisting infection is a major challenge for endodontist. Here we tested two newly developed quaternary ammonium methacrylates (QAMs) against endodontic bacteria and their biofilms. Their antibacterial and antibiofilm efficiency were compared with chlorhexidine (CHX) and sodium hypochlorite (NaOCl). We measured the MIC, MBC and MBIC of DMADDM and DMAHDM respectively. We also detected the ratio of live/dead bacteria and bacterial composition in the biofilms treated by DMADDM and DMAHDM. We found that DMADDM and DMAHDM could inhibit the growth of bacteria and biofilms formation. The result showed that novel QAMs were remarkably efficient than CHX against biofilms. In addition, we found that Streptococcus gordonii (S. gordonii) and Enterococcus faecalis (E. faecalis) were frequent isolates after treatment with antimicrobial compounds.

Highlights

Persistent apical periodontitis is a kind of root canal treatment failure, which mainly caused by persistent or secondary microorganisms infection[1]
The present study investigated the antibacterial and antibiofilm property of DMADDM and dimethylaminohexadecyl methacrylate (DMAHDM) against CHX and NaOCl in multispecies biofilm for the first time
The results indicated that DMADDM and DMAHDM could significantly kill bacteria and disrupt biofilms in endodontic bacteria (P < 0.05)

Summary

Introduction

Persistent apical periodontitis is a kind of root canal treatment failure, which mainly caused by persistent or secondary microorganisms infection[1]. It has been reported that Enterococcus faecalis (E. faecalis), Streptococcus gordonii (S. gordonii), Actinomyces naeslundii (A. naeslundii), and Lactobacillus acidophilus (L. acidophilus) were the “core microbiome” because of the high detection rate and stable co-culture station in vitro. Among these microbes, E. faecalis is common isolates from infected root canal. Two quaternary ammonium methacrylate’s (QAMs) compound, dimethylaminododecyl methacrylate (DMADDM), and dimethylaminohexadecyl methacrylate (DMAHDM) are developed. When they were incorporated in different dental materials, they showed lasting and remarkable antibacterial effect and good biocompatibility. We hypothesized that DMADDM and DMAHDM could inhibit the growth of bacteria and the formation of biofilms

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