title: Morphological alterations of radicular dentine pretreated with different irrigating solutions and irradiated with 980-nm diode laser.
abstract: BACKGROUND
  The topographical features of intraradicular dentine pretreated with sodium hypochlorite (NaOCl) or ethylenediamine tetraacetic acid (EDTA) followed by diode laser irradiation have not yet been determined.
  
  
  OBJECTIVE
  To evaluate the alterations of dentine irradiated with 980-nm diode laser at different parameters after the surface treatment with NaOCl and EDTA.
  
  
  METHODS
  Roots of 60 canines were biomechanically prepared and irrigated with NaOCl or EDTA. Groups were divided according to the laser parameters: 1.5 W/CW; 1.5 W/100 Hz; 3.0 W/CW; 3.0 W/100 Hz and no irradiation (control). The roots were splited longitudinally and analyzed by scanning electron microscopy (SEM) in a quali-quatitative way. The scores were submitted to two-way Kruskal-Wallis and Dunn's tests.
  
  
  RESULTS
  The statistical analysis demonstrated that the specimens treated only with NaOCl or EDTA (control groups) were statistically different (P < 0.05) from the laser-irradiated specimens, regardless of the parameter setting. The specimens treated with NaOCl showed a laser-modified surface with smear layer, fissures, and no visible tubules. Those treated with EDTA and irradiated by laser presented absence of smear layer, tubules partially exposed and melting areas.
  
  
  CONCLUSIONS
  The tested parameters of 980-nm diode laser promoted similar alterations on dentine morphology, dependent to the type of surface pretreatment.
authors.affiliation: Department of Dentistry, School of Dentistry, University of Ribeirão Preto, Ribeirão Preto, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Alfredo
authors.forename: Aline E
authors.initials: AE
authors.lastname: Souza-Gabriel
authors.forename: Silvio Rocha C
authors.initials: SR
authors.lastname: Silva
authors.forename: Manoel D
authors.initials: MD
authors.lastname: Sousa-Neto
authors.forename: Aldo
authors.initials: A
authors.lastname: Brugnera-Junior
authors.forename: Yara T C
authors.initials: YT
authors.lastname: Silva-Sousa
mesh_terms: D003804:Dentin / Q000187:drug effects / Q000528:radiation effects* / Q000648:ultrastructure*; D004492:Edetic Acid / Q000494:pharmacology; D006801:Humans; D054023:Lasers, Semiconductor; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000494:pharmacology; D018915:Root Canal Preparation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D014092:Tooth Root / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure
chemical_list: D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite