title: Ultramorphological and histochemical changes after ER,CR:YSGG laser irradiation and two different irrigation regimes.
abstract: The purpose of this study was to evaluate the ultramorphological and chemical changes in Er,Cr:YSGG laser-treated radicular dentin in comparison with two different irrigation regimes. Extracted human premolars were assigned into three experimental groups. Group 1: After each file size, root canals were irrigated with 5.25% NaOCL, followed by a final irrigation with 5.25% NaOCL. Group 2: At each file size, biomechanical preparation was performed in conjunction with Rc-Prep, followed by 5.25% NaOCL irrigation; and 5.25% NaOCL for the final flush. Group 3: 5.25% NaOCL was used after each file size, followed by Er,Cr:YSGG laser irradiation; and a final flush with 5.25% NaOCL. Scanning electron microscopic (SEM) evaluations revealed failure of smear removal in NaOCL-irrigated specimens. RC-Prep + NaOCL-treated dentin revealed moderate-to-total presence of the smear layer with distinct areas of exposed collagen. Er,Cr:YSGG laser irradiation of radicular dentin also resulted in partial or total removal of the smear associated with a few small regions of thermal injury, including carbonization and partial melting. Energy dispersive X-ray analysis (SEM-EDX) showed no significant difference between the Ca/P ratios of the test groups, suggesting absence of changes at the molecular level.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey. emresan@gmail.com
authors.forename: Emre
authors.initials: E
authors.lastname: Altundasar
authors.forename: Bahar
authors.initials: B
authors.lastname: Ozçelik
authors.forename: Zafer C
authors.initials: ZC
authors.lastname: Cehreli
authors.forename: Koukichi
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D001641:Bicuspid; D002118:Calcium / Q000032:analysis; D002857:Chromium; D003804:Dentin / Q000737:chemistry / Q000648:ultrastructure; D004577:Electron Probe Microanalysis; D004871:Erbium; D006801:Humans; D053685:Laser Therapy; D008274:Magnesium / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D016369:Smear Layer; D012973:Sodium Hypochlorite; D018709:Statistics, Nonparametric
chemical_list: C510180:RC Sealer; D012387:Root Canal Filling Materials; D012388:Root Canal Irrigants; D002857:Chromium; D010758:Phosphorus; D004871:Erbium; D012973:Sodium Hypochlorite; D008274:Magnesium; D002118:Calcium