The Effectiveness of Chelating Solutions and Photodynamic Therapy in Inactivating Bacterial Lipopolysaccharides During Endodontic Therapy

Objective: The purpose of this study was to evaluate the influence effects of different endodontic treatments –, such as chelation ng solutions and antimicrobial photodynamic therapy (aPDT), on the rreductionng the amount of endotoxin levels in root canals.
Methods: Eighty human single-rooted teeth had their crowns sectioned, and the root canals were prepared. All samples and materials were sterilized using Cobalt-60 irradiation. Subsequently, 10 µL of fresh lipopolysaccharide (LPS) was inoculated into the root canals and incubated for 3 days. On the fourth day, experimental treatments were applied to the root canals according to the groups (n=10): [1] pyrogen-free water, [2] 0.005% methylene blue, [3] diode LASER, and [4] 0.005% methylene blue + diode LASER (PDT), [5] 2.5% sodium hypochlorite, [6] 17% trisodium ethylenediaminetetraacetic acid (EDTA), [7] 10% tetrasodium EDTA, [8] 18% etidronate (HEBP). The exposure time for each solution and light irradiation was 5 minutes. The samples collected after treatment were analyzed using the Limulus Amebocyte Lysate test to quantify endotoxins. The data obtained were subjected to Kruskal-Wallis analysis followed by Dunn’s test.
Results: All treatments demonstrated efficacy in reducing endotoxin levels in root canals compared to the use of pyrogen-free water (control). A statistically significant reduction was observed in the groups treated with 17% EDTA and 18% HEBP compared to the control group.
Conclusion: Short-term application (5 minutes) of 17% EDTA and 18% HEBP chelating solutions significantly reduced LPS in root canals and may be effective adjuncts in endodontic therapy. (EEJ-2025-03-032)