Cyotoxicity of Etidronate as an Endodontic Chelator Against Periodontal Ligament Fibroblast

Etidronic acid (HEBP) causes fewer alterations in dentine and can be used mixed with sodium hypochlorite during root canal preparation. This study investigated the cytotoxicity effects of the HEDP and EDTA on human periodontal ligament fibroblast cells. Primary culture was established from human periodontal ligament tissue of one donor and was characterised by immunofluorescence and real-time quantitative polymerase chain reaction. The half-maximal inhibitory concentration (IC₅₀) was tested: 9% HEBP, 18% HEBP, 24% HEBP, 15% EDTA, 17% EDTA, 24% EDTA, and control. Exposure times were 1, 4, and 24 h. The Kruskal-Wallis test, followed by Dunn's post hoc, assessed multiple comparisons between the groups (α = 0.05). All experimental groups showed a lower IC₅₀ effect after 24 h, except 9% HEBP. EDTA cytotoxicity depends on the contact time, regardless of the concentration. In conclusion, 9% HEBP is a biocompatible alternative to EDTA as an endodontic chelator, particularly for protocols requiring longer exposure times.