title: Effects of EDTA on the hydration mechanism of mineral trioxide aggregate.
abstract: Ethylenediaminetetraacetic acid (EDTA) is commonly used during the preparation of obstructed root canals that face a high risk of root perforation. Such perforations may be repaired with mineral trioxide aggregate (MTA). Due to EDTA's ability to chelate calcium ions, we hypothesized that EDTA may disrupt the hydration of MTA. Using scanning electron microscopy and energy-dispersive x-ray spectroscopy, we found that MTA specimens stored in an EDTA solution had no crystalline structure and a Ca/Si molar ratio considerably lower than those obtained for specimens stored in distilled water and normal saline. Poor cell adhesion in EDTA-treated MTA was also noted. X-ray diffraction indicated that the peak corresponding to portlandite, which is normally present in hydrated MTA, was not shown in the EDTA group. The microhardness of EDTA-treated specimens was also significantly reduced (p < 0.0001). These findings suggest that EDTA interferes with the hydration of MTA, resulting in decreased hardness and poor biocompatibility.
authors.affiliation: Graduate Institute of Clinical Dentistry, College of Medicine, National Taiwan University and National Taiwan University Hospital, No. 1 Chang-Te Street, Taipei 10016, Taiwan, ROC.
authors.forename: Y-L
authors.initials: YL
authors.lastname: Lee
authors.forename: F-H
authors.initials: FH
authors.lastname: Lin
authors.forename: W-H
authors.initials: WH
authors.lastname: Wang
authors.forename: H H
authors.initials: HH
authors.lastname: Ritchie
authors.forename: W-H
authors.initials: WH
authors.lastname: Lan
authors.forename: C-P
authors.initials: CP
authors.lastname: Lin
mesh_terms: D000042:Absorption; D017607:Aluminum Compounds / Q000032:analysis / Q000737:chemistry*; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002118:Calcium / Q000032:analysis; D017610:Calcium Compounds / Q000032:analysis / Q000737:chemistry*; D002448:Cell Adhesion; D002478:Cells, Cultured; D002614:Chelating Agents / Q000737:chemistry*; D003460:Crystallization; D003782:Dental Pulp / Q000166:cytology; D004338:Drug Combinations; D004492:Edetic Acid / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D006244:Hardness; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000032:analysis / Q000737:chemistry*; D011897:Random Allocation; D051381:Rats; D012387:Root Canal Filling Materials / Q000032:analysis / Q000737:chemistry*; D017640:Silicates / Q000032:analysis / Q000737:chemistry*; D012825:Silicon / Q000032:analysis; D012965:Sodium Chloride / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D001672:Biocompatible Materials; D017610:Calcium Compounds; D002614:Chelating Agents; D004338:Drug Combinations; D010087:Oxides; D012387:Root Canal Filling Materials; D017640:Silicates; C086631:mineral trioxide aggregate; D014867:Water; D012965:Sodium Chloride; D004492:Edetic Acid; D002118:Calcium; D012825:Silicon