The Effect of the Enzymes Trypsin and DNase I on the Antimicrobial Efficiency of Root Canal Irrigation Solutions

Abstract

Abstract Objectives The purpose of this study was to use a confocal laser scanning microscope (CLSM) to evaluate the antibacterial efficacy of using 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), Irritrol, and chitosan-coated silver nanoparticles (AgCNPs) alone or in combination with deoxyribonuclease I (DNase I) and trypsin pre-enzyme applications in dentin samples contaminated with Enterococcus faecalis (E. faecalis).Materials and Methods 144 dentin blocks with confirmed E. faecalis biofilm formation were divided randomly according to the irrigation protocol to be tested (n = 12): NaOCl, CHX, Irritrol, AgCNPs, Trypsin/ NaOCl, Trypsin/ CHX, Trypsin/ Irritrol, Trypsin/ AgCNPs, DNase I/ NaOCl, DNase I/ CHX, DNase I/ Irritrol, and DNase I/ AgCNPs. Dentin blocks were stained with the Live/Dead BacLight Bacterial Viability Kit and viewed with CLSM after irrigation applications. The percentage of dead and viable bacteria was calculated using ImageJ software on CLSM images. At a significance level of p < 0.05, the obtained data were analyzed using One-Way Anova and Post-Hoc Tukey tests.Results In comparison to NaOCl, CHX had a higher percentage of dead bacteria, both when no pre-enzyme was applied and when DNase I was applied as a pre-enzyme (p < 0.05). There was no difference in the percentage of dead bacteria between the irrigation solutions when trypsin was applied as a pre-enzyme (p > 0.05). AgCNPs showed a higher percentage of dead bacteria when trypsin was applied as a pre-enzyme compared to other irrigation solutions (p < 0.05), while the pre-enzyme application did not affect the percentage of dead bacteria in NaOCl, CHX, and Irritrol (p > 0.05).Conclusions No irrigation protocol tested was able to eliminate the E. faecalis biofilm. While the application of trypsin as a pre-enzyme improved the antimicrobial effect of AgCNPs, it did not make any difference over other irrigation solutions.Clinical Relevance: Pre-enzyme treatment with trypsin improved the antimicrobial activity of AgCNPs. The combined use of these two solutions may be useful as a treatment support in endodontic practice, as it helps to separate bacteria from the biofilm matrix.