Effect of different chelating agents, with and without activation, including XP-endo Finisher, on root dentin microhardness: An in vitro study

Introduction: Irrigating solutions used during root canal preparation may affect the physical properties of dentin. Therefore, careful selection of irrigants is required which have maximum benefits with minimum undesirable properties. The rationale of the study was to use a natural alternative to ethylenediaminetetraacetic acid (EDTA) that can be activated using XP endo-Finisher to shorten the time of exposure to avoid EDTA detrimental effect on dentin microhardness. Materials and Methods: Sixty freshly extracted single-rooted teeth used after disinfection using 5% sodium hypochlorite for 30 min. Later, crowns were removed where only 8-mm long segments from the middle and apical parts of the roots were used. They were embedded into autopolymerizing acrylic resin. ProTaper Next nickel–titanium files were used for shaping canals up to size X3. Silicon carbide paper and felt wheel were used for polishing coronal surface of the segments. Thin specimens were sectioned into six groups: saline, EDTA, and phytic acid without and with activation. Vickers microhardness tester was used with a 300-g load and 20-s dwell time for measuring microhardness before and after treatment at 100 μm and 500 μm from the root canal lumen. Mean Vickers hardness number and change percentage in microhardness were calculated. Results: Phytic acid and EDTA decreased root canal dentin microhardness significantly at 100 μm and nonsignificantly at 500 μm either with or without activation by XP-endo Finisher. Conclusion: All the used chelating solutions affected the microhardness of root canal dentin.