title: Chemical and morphological changes in human dentin after Er:YAGlaser irradiation: EDS and SEM analysis.
abstract: Sixty samples of human dentin were divided into six groups (n = 10) and were irradiated with Er:YAG laser at 100 mJ-19.9 J/cm(2), 150 mJ-29.8 J/cm(2), 100 mJ-35.3 J/cm(2), 150 mJ-53.0 J/cm(2), 200 mJ-70.7 J/cm(2), and 250 mJ-88.5 J/cm(2), respectively, at 7 Hz under a water spray. The atomic percentages of carbon, oxygen, magnesium, calcium, and phosphorus and the Ca-to-P molar ratio on the dentin were determined by energy dispersive X-ray spectroscopy. The morphological changes were observed using scanning electron microscopy. A paired t-test was used in statistical analysis before and after irradiation, and a one-way ANOVA was performed (P ≤ 0.05). The atomic percent of C tended to decrease in all of the groups after irradiation with statistically significant differences, O and Mg increased with significant differences in all of the groups, and the Ca-to-P molar ratio increased in groups IV, V, and VI, with statistically significant differences between groups II and VI. All the irradiated samples showed morphological changes. Major changes in the chemical composition of dentin were observed in trace elements. A significant increase in the Ca-to-P ratio was observed in the higher energy density groups. Morphological changes included loss of smear layer with exposed dentinal tubules. The changes produced by the different energy densities employed could have clinical implications, additional studies are required to clarify them.
authors.affiliation: Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México.
authors.forename: Belinda
authors.initials: B
authors.lastname: Contreras-Arriaga
authors.affiliation: Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México.
authors.forename: Laura Emma
authors.initials: LE
authors.lastname: Rodríguez-Vilchis
authors.affiliation: Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México.
authors.forename: Rosalía
authors.initials: R
authors.lastname: Contreras-Bulnes
authors.affiliation: Universidad Autónoma Del Estado de México-Universidad Nacional Autónoma de México, Centro Conjunto de Investigación en Química Sustentable (CCIQS), Km 14.5 Carretera Toluca-Ixtlahuaca, San Cayetano de Morelos, Toluca, Estado de México, C.P. 50200, México.
authors.forename: Oscar Fernando
authors.initials: OF
authors.lastname: Olea-Mejìa
authors.affiliation: Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México.
authors.forename: Rogelio José
authors.initials: RJ
authors.lastname: Scougall-Vilchis
authors.affiliation: Facultad de Odontología, Centro de Investigación y Estudios Avanzados en Odontología (CIEAO), Universidad Autónoma del Estado de México, Jesús Carranza Esq. Paseo Tollocan, Col. Universidad, Toluca, Estado de México, C.P. 50130, México.
authors.forename: Claudia
authors.initials: C
authors.lastname: Centeno-Pedraza
mesh_terms: D002118:Calcium / Q000032:analysis; D002244:Carbon / Q000032:analysis; D003804:Dentin / Q000737:chemistry* / Q000528:radiation effects*; D004602:Elements; D006801:Humans; D053844:Lasers, Solid-State; D028022:Low-Level Light Therapy; D008274:Magnesium / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D016369:Smear Layer / Q000648:ultrastructure; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties
chemical_list: D004602:Elements; D010758:Phosphorus; D002244:Carbon; D008274:Magnesium; D010100:Oxygen; D002118:Calcium
keywords: EDS; Er:YAG laser; SEM; chemical; dentin; morphological