title: Biochemical composition of carious dentin and different layers of sound dentin.
abstract: The aim of this study was to evaluate the concentrations of calcium (Ca), inorganic phosphate (Pi) and fluoride (F) in carious dentin and in different layers of sound dentin. The samples examined were 52 permanent teeth (26 sound and 26 carious), which were subjected to two experiments to assess the mineral content of: 1) two layers (internal and external) of sound dentin and 2) sound and carious dentin. Ca and Pi were analyzed using a colorimetric method with arsenazo III (C22H18As2N4O14S2) and molybdate reagents, and F was analyzed using a specific electrode. A non-parametric test, the Mann-Whitney test, was used to verify differences between groups. Sound dentin showed a higher concentration of fluoride in the internal layer than in the external layer (P = 0.03), but no inter-layer differences in Ca or Pi concentration were evident. Lower concentrations of Ca, Pi and F were observed in carious dentin than in sound dentin (P < 0.05). The results of this study suggest that the internal layer of sound dentin has a higher fluoride content than the external layer, and that carious dentin has lower concentrations of Ca, Pi and F than sound dentin.
authors.affiliation: Department of Preventive and Social Dentistry, Faculty of Dentistry, Federal University of Rio Grande do Sul, Brazil.
authors.forename: Larissa
authors.initials: L
authors.lastname: Magnus
authors.forename: Marisa
authors.initials: M
authors.lastname: Maltz
authors.forename: Caren
authors.initials: C
authors.lastname: Bavaresco
authors.forename: Lucelen F
authors.initials: LF
authors.lastname: Bastos
authors.forename: Lina N
authors.initials: LN
authors.lastname: Hashizume
mesh_terms: D001150:Arsenazo III; D002118:Calcium / Q000032:analysis; D003124:Colorimetry / Q000379:methods; D004396:Coloring Agents; D003731:Dental Caries / Q000473:pathology*; D003804:Dentin / Q000737:chemistry*; D005459:Fluorides / Q000032:analysis; D006801:Humans; D007202:Indicators and Reagents; D017736:Ion-Selective Electrodes; D008963:Molar / Q000737:chemistry; D008964:Molar, Third / Q000737:chemistry; D008982:Molybdenum; D010710:Phosphates / Q000032:analysis
chemical_list: D004396:Coloring Agents; D007202:Indicators and Reagents; D010710:Phosphates; C044659:molybdate; D001150:Arsenazo III; D008982:Molybdenum; D005459:Fluorides; D002118:Calcium