title: Efficacy of solution form of ethylenediaminetetraacetic acid on removing smear layer of root canal at different exposure time In Vitro.
abstract: This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid (EDTA) on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups: control group (group A) was given 2.5% NaOCl, and 4 experimental groups were given 2.5% NaOCl and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning electron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A (P>0.05). In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups (P>0.05), but there was significant difference in removal of smear layer between group C and group B (P<0.05). Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D (P<0.01). There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOCl could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.
authors.affiliation: Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
authors.forename: Sitashi
authors.initials: S
authors.lastname: Poudyal
authors.affiliation: Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China. pweihong@sina.com.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Pan
authors.affiliation: Hospital of Huazhong University of Science and Technology, Wuhan, 430060, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Zhan
mesh_terms: D000293:Adolescent; D001641:Bicuspid / Q000601:surgery / Q000648:ultrastructure; D002614:Chelating Agents / Q000627:therapeutic use; D004492:Edetic Acid / Q000627:therapeutic use*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000379:methods; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000627:therapeutic use*; D012996:Solutions; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D002614:Chelating Agents; D012388:Root Canal Irrigants; D012996:Solutions; D004492:Edetic Acid; D012973:Sodium Hypochlorite