title: Ultrastructural evaluation of radicular dentin after Nd:YAG laser irradiation combined with different chemical substances.
abstract: This aticle sought to evaluate the dentin morphology after irradiation by a Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser, using different chemical substances to irrigate radicular canals: distilled water, 17% ethylenediaminetetraacetic acid plus Cetavlon (EDTAC), 1% sodium hypochlorite, and 2% chlorhexidine. Groups were subdivided according to the protocol of laser application (n=9). The specimens were analyzed by scanning electron microscopy (SEM). No differences were found in dentin morphology when different root thirds were examined. Regardless of the chemical substance used, alterations were more evident in groups in which the surfaces were dried before laser irradiation. Fusion areas, craters, carbonization, and partially exposed tubules were verified. When the irradiation was performed in water, the smear layer was incorporated into the laser-modified surface. Among the specimens irrigated with EDTAC and laser-treated, partial obliteration of dentin tubules due to the laser action was verified; in addition, there was no remaining smear layer on the surfaces. Samples irrigated with sodium hypochlorite followed by laser irradiation demonstrated similar morphology to the samples in the chlorhexidine group, with some fusion areas present and no exposed dentin tubules or fissures. The irradiation from an Nd:YAG laser in the presence of EDTAC solution provided a more favorable surface pattern compared to the other experimental conditions, due to the removal of the contaminated layer and the posterior sealing of dentin tubules.
authors.affiliation: University of Ribeirao Preto, Brazil.
authors.forename: Maria Isabel Anastacio
authors.initials: MI
authors.lastname: Faria
authors.forename: Aline Evangelista
authors.initials: AE
authors.lastname: Souza-Gabriel
authors.forename: Melissa Andreia
authors.initials: MA
authors.lastname: Marchesan
authors.forename: Manoel Damiao
authors.initials: MD
authors.lastname: Sousa-Neto
authors.forename: Yara Teresinha Correa
authors.initials: YT
authors.lastname: Silva-Sousa
mesh_terms: D000891:Anti-Infective Agents, Local / Q000627:therapeutic use; D002244:Carbon; D002614:Chelating Agents / Q000627:therapeutic use; D002710:Chlorhexidine / Q000627:therapeutic use; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D003804:Dentin / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D003890:Desiccation; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D028022:Low-Level Light Therapy; D008855:Microscopy, Electron, Scanning; D012388:Root Canal Irrigants / Q000145:classification / Q000627:therapeutic use*; D018915:Root Canal Preparation; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D014867:Water
chemical_list: D000891:Anti-Infective Agents, Local; D002614:Chelating Agents; D012388:Root Canal Irrigants; D014867:Water; C033443:EDTAC; D002244:Carbon; D004492:Edetic Acid; D012973:Sodium Hypochlorite; D002710:Chlorhexidine