An In-Vitro Evaluation of the Antimicrobial Efficacy of a Novel Irrigant

Abstract

Aim: To evaluate the antimicrobial activity of Triton irrigation and conventional irrigation utilizing NaOCl and EDTA separately. Methodology: Twenty-four extracted mandibular single rooted teeth were collected. Teeth were inoculated with subgingival human-derived dental plaque for 2 weeks utilizing a CDC biofilm reactor. Teeth were assigned into two treatment groups, conventional (NaOCl irrigation) or Triton irrigation group. Sterile paper points were used to collect the pre and post-treatment samples from the canals. All microbiological samples were stored at −80°C prior to DNA extraction and analysis. Samples were obtained for 16S ribosomal RNA gene sequencing (Next Generation Sequencing - NGS). Differences in abundances of genera were evaluated using Kruskal–Wallis test, and differences in alpha diversity were compared using ANOVA. The Shannon and Chao1 indices were used to measure alpha diversity. The Bray–Curtis dissimilarity was used to measure beta diversity. Differences in community composition were evaluated using analysis of similarity (ANOSIM) with Bonferroni correction for multiple comparisons. Results: NGS analysis showed that fewer reads and operational taxonomic units (OTUs) were obtained from post-treatment samples in both experimental groups (P < 0.0001). Communities in pre-treatment samples were similar in both groups according to beta diversity analysis (ANOSIM R-value=0.048, p-value=0.18). Beta diversity analysis showed significant differences between the NaOCl and Triton post-treatment communities (ANOSIM p-value=0.008, Bonferroni-corrected α = 0.008). No significant differences in alpha diversity between both post-treatment groups were observed (P > 0.05). The Kruskal Wallis 2-way analysis found that 17 genera of bacteria were overrepresented in the Triton post-treatment group. Conclusion: While both irrigation protocols showed significant antimicrobial efficacy, the conventional technique (NaOCl followed by EDTA flush) technique was more effective in removing bacterial DNA in teeth infected in-vitro.