Obscure Fact of Ethylene Diamine Tetra Acetic Acid (EDTA) on Radicular Dentine: An In-vitro Study

Background: Chelating agents are used to dissolve radicular dentin and eliminate the smear layer that develops after root canal preparation by mechanical means. By functioning as a barrier, the smear layer keeps irrigants from coming into direct touch with the dentin surface and dentinal tubules, cleaning them, and compromising the obturation's sealing qualities. Chelators like etidronic acid (1-hydroxyethane-1,1-diphosphonic acid [HEDP] pH 11) and phytic acid (PA) (inositol hexakisphosphate pH 1.3) have been suggested as EDTA substitutes recently. However, studies have shown that long-term usage of strong chelators, such as EDTA, may be detrimental to the biomechanical properties of root dentin, as seen by a decline in flexural strength and microhardness.

Aim and Objective: The objective of this in vitro study was to examine the impact of different endodontic chelating agents on the flexural strength and micro hardness of radicular dentin.

Materials and Methods: Fourty dentin sticks were obtained from 10 single‑rooted premolars and divided into four groups (n = 10). One stick from each tooth was assigned to one of the experimental groups and was soaked in one of the experimental chelating solutions for 10 min, and 15 min in 17% ethylenediaminetetraacetic acid (EDTA), 2.5% phytic acid (PA), 18% etidronic acid, or saline (control group). Following the 10 min, and 15 min soak, the stick’s flexural strength was evaluated using a 3‑point loading test using the universal testing machine, and the surface microhardness was tested using a Vickers’s microhardness tester.

Results: EDTA showed lower microhardness and flexure strength compared with the phytic acid and Etidronic acid.

Conclusion: Given the limits of this investigation, it can be stated that both 2.5% Phytic acid and 18% Etidronic acid chelators do not significantly degrade the surface and bulk mechanical properties of radicular dentin when compared to EDTA.