Biological and chemical properties of new multi-functional root canal irrigants

To evaluate the efficacy of multi-functional root canal irrigating solutions in the removal of canal wall smear layers, antibacterial activity, cytotoxicity, and tissue dissolution efficacy.

Forty single-rooted teeth were mechanically instrumented and irrigated with Triton, EndoJuice™, EDTA, and 0.9 % saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Antibacterial activity of the irrigants was assessed against Enterococcus faecalis biofilms using colony-forming unit analysis. Neutral red, clonogenic, and cytokinesis-block micronucleus assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity and genotoxicity of the irrigants. Tissue dissolution efficacy was tested on shrimp meat placed in resorptive cavities prepared in root canals.

EndoJuice™ and EDTA showed better smear layer removal than Triton in the coronal-third and middle-third of the canal walls. There was no significant difference between EndoJuice™ and EDTA. In the apical-third, EndoJuice™ removed the smear layer more effectively than EDTA and Triton. Specimens treated with saline were heavily smeared. Triton and sodium hypochlorite were similar in reducing intracanal E. faecalis counts, while specimens treated with EndoJuice™ had higher colony-forming units compared to Triton or sodium hypochlorite. EndoJuice™ was less cytotoxic and genotoxic compared to Triton. Sodium hypochlorite dissolved the most soft tissue, followed by Triton and EndoJuice™.

EndoJuice™ was less toxic and more effective in smear layer removal. Triton demonstrated better antimicrobial activity and tissue dissolution efficacy.

Evaluating the smear layer removal, antibacterial activity, toxicity, and tissue dissolution abilities of multi-functional root canal irrigants is essential to ensure their effectiveness and safety for clinical use in root canal treatment.