title: Effects of Er:YAG laser irradiation and manipulation treatments on dentin components, part 2: energy-dispersive X-ray fluorescence spectrometry study.
abstract: The effects of laser etching, decontamination, and storage treatments on dentin components were studied by energy-dispersive X-ray fluorescence spectrometry (EDXRF). Thirty bovine incisors were prepared to expose the dentin surface and then divided into two main groups based upon the decontamination process and storage procedure: autoclaved (group A, n=15) or stored in aqueous thymol solution (group B, n=15). The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control subgroup) or irradiated with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser (subgroups: I-80 mJ, II-120 mJ, and III-180 mJ). Samples were analyzed by micro-EDXRF, yielding three spectra for each area (before and after treatment). Surface mappings covering an area of 80x60 points with steps of 20 mum were also performed on selected specimens. The amount of Ca and P in group A specimens decreased significantly (P<0.05) after the acid etching and the CaP ratio increased (P<0.001). Er:YAG laser-etching using lower laser energies did not produce significant changes in dentin components. The mapping data support the hypothesis that acid etching on dentin produced a more chemically homogeneous surface and thus a more favorable surface for the diffusion of adhesive monomers.
authors.affiliation: Vale do Paraiba University, UNIVAP, Dental Materials and Operative Dentistry Department, School of Dentistry Research and Development Institute, 12244-000 Sao Jose dos Campos, Sao Paulo, Brazil. lesoares@univap.br
authors.forename: Luís Eduardo Silva
authors.initials: LE
authors.lastname: Soares
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: do Espírito Santo
authors.forename: Aldo
authors.initials: A
authors.lastname: Brugnera
authors.forename: Fátima Anto Nia Aparecida
authors.initials: FA
authors.lastname: Zanin
authors.forename: Airton Abrahão
authors.initials: AA
authors.lastname: Martin
mesh_terms: D000818:Animals; D002417:Cattle; D003804:Dentin / Q000737:chemistry* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D007180:Incisor / Q000737:chemistry / Q000528:radiation effects; D053844:Lasers, Solid-State; D011829:Radiation Dosage; D013052:Spectrometry, X-Ray Emission / Q000379:methods*